Which company's SSD drive is better? Can I install an SSD in my laptop? Physical compatibility of interfaces

A solid state drive is not much different in appearance from a HDD.

The abbreviation SSD stands for Solid State Drive. You can translate it into Russian as a solid-state drive. Its main advantage is the absence of moving internal parts, that is, all operations are performed by electronic units.

In fact, the first solid state drive appeared in 1978. But in those days, the benefits of its use were very doubtful, and production was costly. SSDs were introduced to the general public around 2007-2008. They were modest in memory size and could have around 128 GB. Nowadays, there are already models of solid-state drives with a capacity of 1 TB and read/write speeds of 2600/1600 MB/s. And not so long ago, the Russian company GS Group began producing SSDs.

In a special publication on our portal, we will talk in detail about what RAM is in a computer. You will learn the characteristics of RAM, how to find out the amount of RAM and types of RAM on your computer.

Difference between SSD and HDD

The most important difference is in the design. An SSD has no moving parts, which means there is nothing inside it to wear out. And as a result - the absence of noise. Due to the fact that all the elements inside the SSD are soldered and secured, such a drive is much more resistant to shocks and vibrations.

On a HDD, files are read by passing the magnetic head over the surface of the disk. The reading and writing speed in this case depends on the disk rotation speed. In an SSD, there is no magnetic disk as such, and reading occurs by checking the memory cells for the presence of charge in them, which is undoubtedly faster.

The same applies to random access to data. For example, to simultaneously read several different HDD files, its magnetic head will have to “rush” between different sections of the disk to ensure timely loading of data. An SSD can simultaneously find and load several files at once.

Well, another significant advantage is low energy consumption.

Well, now it’s worth remembering the shortcomings. The most important of them, because of which many users were initially afraid to switch to SSDs, is the limited number of rewrite cycles. In other words, the more often data on a disk is overwritten, the sooner it will fail. Moreover, this happened at the most unexpected moments for the user. But the technology is improving, mechanisms are being added to control the number of cell rewrites, which allow you to add new data to less “worn-out” ones. Memory types are also being upgraded, which will further extend the life of the device.

Another repulsive factor is the price of the SSD drive. But this is a temporary phenomenon, as the cost is gradually decreasing. For example, today an average quality 500 GB disk can be bought for about 9,000 rubles. A HDD of this volume can be purchased for 2,000–3,000 rubles, with a disk rotation speed of 7200 rpm.

Well, the last thing worth knowing about SSDs is the impossibility of recovering files after deletion. Although some manufacturers provide their devices with mechanisms that allow this to be done. Perhaps in the future we will see an SSD with all the capabilities of an HDD, but without its disadvantages.

Main technical characteristics of SSD drives for PCs

The main parameters by which it is customary to choose an SSD are: volume, form factor, connection type and read/write speeds. But, besides them, there are other, less popular options. Let's look into all the intricacies of the characteristics and find out which SSD to choose when purchasing.

Volume

It makes no sense to explain specifically about the capacity of a hard drive in our digital age. In short, it characterizes the maximum amount of data that can be written to it. It is measured in gigabytes and, more recently, in terabytes. 1TB = 1000 GB.

Disk board

This is interesting: in fact, there is a little confusion with terabytes, as with other units - gigabytes and megabytes. The fact is that almost all applications and OS use 1024 GB as a terabyte. But in the SI unit measurement system, the prefix “tera” means 1012, that is, exactly 1,000,000,000,000. Almost all hard drive manufacturers adhere to the “correct” metric: 1 TB = 1000 GB. But the operating system can calculate and display the volume in its own way, based on 1TB = 1024 GB.

In general, the main selection criterion is the more, the better.

Form factor

There are 4 main form factors present on the market: 1.8“, 2.5“, 3.5“ and several varieties of M.2. The first two standards are usually used as a laptop SSD hard drive. The rest are more common on desktop versions of PCs. If everything is clear with inches, then M.2 is worth understanding in more detail.

Form factor 2.5"

M.2 is a relatively new specification of connectors and boards. Mainly used to connect SSDs, but other devices are also present, such as USB, Wi-Fi modules, etc. In most cases, there are SSDs with M and B keys. This is easy to determine - there will be three separate buses on the board: two small and one large in the middle. Also, boards are divided into 2242, 2260, 2280. This is nothing more than the size. The first two digits indicate the width, the rest - the length.

Form factor M.2 and its varieties

ATTENTION!

Before installing an SSD drive on your computer, you should make sure that the module does not interfere with other components of the motherboard and cooling.

Connection interface

The connection interface is very closely related to the form factor. The two most popular connection types today are SATA and PCIe. The first option has increased compatibility, as it is present on almost all motherboards, including laptops.

SATA interface cable

PCIe variants are mostly found in desktop systems. Although it should be noted that the M.2 standard is gradually beginning to be adopted by mobile platforms.

Read/write speed

With speeds in the SSD environment, everything is very complicated. Naturally, the read and write speed is much higher than that of an HDD. However, many manufacturers like to significantly inflate these parameters for marketing purposes. Therefore, when choosing, it is better to focus on reviews of authoritative resources and publications, as well as reviews from customers who have already tried the device.

Memory type and runtime to failure

There are three types of SSD memory: SLC, MLC and TLC. At the beginning of 2017, Intel announced a new type of memory, but the device is still too expensive and it is not yet known how long it will take for it to reach the average user. So these three known types are used.

SLC stands for Single Level Cell, that is, a single-level cell. The most productive type with the longest service life. However, while their price is relatively high, such SSDs are used mainly in server solutions.

MLC− multi-level cell. We can say that this is an average level between SLC and TLC. Average resource, average productivity, average price.

TLC− the most inexpensive type of memory, weakest in terms of performance and service life. It was this technology that was used to operate conventional flash drives.

TRIM function

This function was needed after the development of the first solid-state drives. The fact is that regular HDDs and SSDs perform deletion and formatting differently. In short, to repeat the technique of these operations on an SSD, like an HDD, the speed and resource of solid-state drives would become uncompetitive.

The TRIM function is used to clear cells before overwriting them. This saves access time for the SSD. Support for its systems began with Windows 7, Linux 2.6.33 and MacOS. Android, starting with version 4.3, has its own analogue of the TRIM function.

THIS IS INTERESTING:

If suddenly your system does not support the TRIM function, then there are several special utilities that perform its duties manually.

Drive clipboard

The buffer or cache on the HDD accelerated the speed of writing and reading due to the accumulation of a certain amount of information in a separate area. This made it possible not to “tug” the hard drive one more time. In an SSD, this approach does not make sense, since writing and reading are already instantaneous. However, in solid-state drives, the cache is often used as a storage device for service information. It does not particularly affect performance, and is rarely indicated by developers in the specifications or information about the device.

What is the difference between expensive and cheap SSDs?

The main parameters that affect the cost of a solid-state drive are the type of memory, type of controller and its capacity. Memory types have already been discussed in the article just above. Controllers depend entirely on the manufacturer. From the top segment we can highlight brands such as Intel, Samsung, Marvell. The class below is followed by Jmicron or Silicon Motion.

Among the latest expensive new products, we can highlight products from Intel with the 3D Xpoint memory type. True, such an SSD disk for a 500 GB computer is sold at a price of about 40,000 rubles. The declared read/write speed on such a device can reach 2000/2500 MB/s.

Which is better for a laptop - HDD or SSD

The technological development of SSDs is still at such a level that using it in a system as the main hard drive is not considered acceptable. This is due to the fact that they fail too quickly compared to HDDs.

Therefore, the best solution for a solid-state hard drive for a laptop is to use it in conjunction with an HDD. You can install the operating system on the SSD, and programs, games, documents and other files on the HDD. If you are planning to buy an SSD drive for an M.2 format laptop, then you should first make sure that this laptop supports this type of connector.

M.2 solid state drive in a laptop

Which laptop SSD is better to choose? You can choose a budget version of the disk with a small capacity (for example, 60 GB), TLC memory type and, if possible, use M.2. This volume should be enough for most operating systems. All programs and games will be installed on an additional HDD, which will increase the service life of the device. If the SSD fails, all data will be saved to the HDD.

What is the best SSD drive for a computer? Review of several models and rating of SSD drives

The market for SSD devices is very diverse. Unlike processors, there are no leading players here. The production of solid-state drives is carried out by both large and famous corporations and little-known companies. However, often a small company can release an interesting, inexpensive and reliable device.

Plextor PX-128S3C - inexpensive SSD drive for PC and laptop

Budget solution for a desktop computer or laptop. It has a 2.5" form factor, which gives it versatility. The type of memory used is TLC, which is typical for inexpensive devices. The stated write/read characteristics are 500/550 MB/s. The test results showed only a slight deviation of these values.

Plextor PX-128S3C

The total memory is 128 GB, cache is 256 MB. According to the developers, the disk will be able to withstand about 35 TB of overwritten data and 1,500,000 hours of operation.

Samsung MZ-75E1T0BW

This SSD differs in that it uses a more modern type of 3D V-NAND memory, an improved version of TLC. It allows you to significantly increase the total volume, which is 1 TB in this SSD.

The controller used is our own - Samsung MEX. It is used in many similar devices and has proven itself to be a reliable and fast module.

Samsung MZ-75E1T0BW

Form factor − 2.5“. This means that the device can be used in both a desktop PC and a laptop. The declared read/write speed is 520/540 MB/s. Own cache is 1024 MB. The operating time declared by the manufacturer is 1,500,000 hours.

Western Digital Green PC SSD 240 GB

Western Digital has been manufacturing storage devices for a long time. Naturally, they couldn’t ignore the SSD format. This model has a capacity of 240 GB, which means it can be used not only as a disk for the operating system, but also as the main data storage. The 2.5" form factor allows you to connect it to both a desktop PC and a laptop. Memory type: budget TLC. According to the developers, the peak speed can be 465 MB/s for writing and 540 MB/s for reading. However, tests show that the write speed can actually be about 200 MB/s.

Western Digital Green PC SSD 240 GB

As for the resource, about 1,750,000 operating hours are stated.

Samsung MZ-N5E250BW

Another representative from a famous brand. It differs from the one already presented in that it is made in the M.2 form factor with a size of 2280 MB, that is, suitable for stationary versions of PCs. But many modern laptops are now also equipped with this slot, so you can use this drive here too. Before purchasing, you should make sure that there is a bus on the motherboard.

Samsung MZ-N5E250BW

The volume of the device is 250 GB, the memory type is 3D V-NAND. Self-produced controller - Samsung MGX. Write/read speed: 500/540 MB/s. Buffer memory - 512 MB.

SmartBuy Ignition 4 240 Gb

A little-known brand that is gradually gaining popularity. The amount of disk space is 240 GB. The form factor is suitable for laptops and PCs - 2.5“. Interestingly, this budget option uses more powerful and reliable MLC memory.

SmartBuy Ignition 4 240 Gb

How to connect an SSD to a computer - basic nuances

There are no special differences from connecting a standard HDD. However, there are a couple of nuances that are best taken care of before installing the device.

Firstly, if the SSD form factor is 2.5", then you will need to buy a special adapter - 3.5", which will allow you to securely mount the drive in the PC case. It is connected to the motherboard via a SATA cable. Secondly, after installing the device, you will need to go into the computer’s BIOS and make sure that the AHCI drive mode is enabled.

One of the adapter options 2.5“ to 3.5“

There is no need to insert a separate adapter into your laptop, since almost all of them support the 2.5“ standard. The connectors are firmly fixed, so you just need to “insert” the disk and close it with the lid.

The SSD drive does not appear on my computer - the main reasons

It often happens that an SSD drive is detected in the BIOS, but does not want to appear in Windows. In most cases, this means there is no volume on the device. Therefore we need to create it.

Disk Management in Windows 7

For Windows 7 you will have to go to the diskmgmt.msc utility. You can find it by searching in the Start menu. The Disk Management window will open. The required SSD will appear as unallocated space. You need to right-click on it and select “Create Volume”.

Enabling SATA and AHCI in BIOS

It happens less often that the disk is not detected in the BIOS. In this case, you should start by checking the status of the SATA controller. It must be turned on. More significant problems may arise due to incompatibility of the motherboard, defective disk, or for a number of other reasons.

What is the most profitable way to buy an SSD drive for a computer and how to buy an SSD drive for a laptop - overview table

We have collected several interesting models in one table, which reflects the characteristics, compatibility with PCs and laptops, prices and features of SSDs.

Device	Peculiarities	Compatibility	Price, rub
Plextor PX-128S3C	Memory type - TLC, form factor − 2.5“, 35 TB of rewritable data.	Laptop, desktop PC.	3 200
Samsung MZ-75E1T0BW	Memory type - 3D V-NAND, form factor − 2.5“, 1,500,000 operating hours.	Laptop, desktop PC.	16 000
WD GREEN PC SSD 240 GB	Memory type - TLC, form factor − 2.5“, 1,750,000 operating hours.	Laptop, desktop PC.	4 500
Samsung MZ-N5E250BW	Memory type - 3D V-NAND, form factor - M.2 2280, 1,500,000 operating hours.	Laptop, desktop PC.	6 000
SmartBuy Ignition 4 240 Gb	Memory type - MLC, form factor - 2.5“.	Laptop, desktop PC.	5 600
Intel SSDSC2BW240H601	240 GB, form factor − 2.5“, memory type – MLC.	Laptop, desktop PC.	28 300
Kingston SE50S37/480G	480 GB, form factor − 2.5“, memory type – MLC.	Server solutions.	23 000

If you have experience managing and working with SSD drives, then feel free to share it in the comments.

I recommend purchasing an SSD drive with an optimal speed/reliability ratio of MLC or 3D NAND memory. Read/write speeds closer to 500/500 MB/s are considered quite high. The minimum recommended speed for more budget SSDs is 450/300 MB/s.

The best brands are: Intel, Samsung, Crucial and SanDisk. As a more budget option you can consider: Plextor, Corsair and A-DATA. Among other manufacturers, problematic models are more common.

For a work or multimedia computer (video, simple games), an SSD with a capacity of 120-128 GB will be sufficient, and here the A-Data Ultimate SU900 on MLC memory would be an excellent choice.
SSD A-Data Ultimate SU900 128GB

A mid-class gaming computer requires a capacity of at least 240-256 GB; an SSD from the A-Data Ultimate SU900 or Samsung 860 EVO series is also suitable.
SSD A-Data Ultimate SU900 256GB

SSD Samsung MZ-76E250BW

For a professional or powerful gaming computer, it is better to take a 480-512 GB SSD, for example Samsung SSD 860 EVO.
SSD Samsung MZ-76E500BW

For computers and laptops with an M.2 connector, a good option would be to install an ultra-fast SSD (1500-3000 MB/s) in the appropriate format.
SSD Samsung MZ-V7E500BW

When choosing a volume, be guided by your needs, but you should not neglect it for the sake of higher speed. If you doubt the correctness of your choice, we recommend reading reviews of specific models.

2. What is the difference between expensive and cheap SSDs

Inexperienced users may be confused why SSD drives of the same volume, with the same declared speed characteristics, differ so much in price, sometimes several times.

The fact is that different SSD drives can use different types of memory, which, in addition to speed indicators, also affects reliability and durability. In addition, memory chips from different manufacturers also differ in quality. Naturally, cheap SSDs are equipped with the cheapest memory chips.

In addition to memory chips, the SSD disk has a so-called controller. This is a chip that controls the processes of reading/writing data into memory chips. Controllers are also produced by different companies and they can be either budget ones with lower speed and reliability, or higher quality ones. Cheap SSDs, as you understand, also have the worst controllers installed.

Many modern SSDs use fast DDR3 memory, just like computer RAM, as a clipboard to further improve performance. Most budget SSDs may not have a clipboard, making them marginally cheaper but significantly slower.

But that's not all, it even comes down to saving on such important components of an SSD drive as capacitors, which are necessary to prevent integrity violations and data loss. In the event of a sudden power outage, the electrical energy stored in the capacitors is used to complete writing from the clipboard to the memory chips. Unfortunately, not all even high-quality SSDs are equipped with backup capacitors.

The layout itself and the quality of the printed circuit board wiring are also different. More expensive models have more sophisticated circuit design, quality components and wiring. The engineering solutions of the most budget SSDs are based on outdated designs and leave much to be desired. The number of defects in cheap SSDs is also higher, which is due to assembly in cheaper factories and lower levels of production control.

And of course, the price depends on the brand; the more famous it is, the more expensive the SSD. Hence, there is an opinion that you should not overpay for a brand. But the fact is that often it is the brand name that determines the quality of an SSD drive. Most well-known manufacturers who value their reputation will not allow themselves to produce low-quality products. However, there are exceptions here, in the form of well-known and popular brands, which nevertheless should not be recommended for purchase.

We will briefly look at the main differences between SSDs that you need to focus on in this article, and you can easily choose the model that suits you.

3. VolumeSSDdisk

Volume is the most important parameter of an SSD disk.

If you only need an SSD drive to speed up the loading of Windows, office programs and increase system responsiveness, then, in principle, a capacity of 60-64 GB (gigabytes) is sufficient.

If you want to speed up the work of serious professional applications (video editing, design systems, etc.), then you will need an SSD drive with a capacity of 120-128 GB.

For a gaming computer, it is advisable to purchase an SSD with a capacity of at least 240-256 GB, since modern games take up a lot of space (30-60 GB each).

In the future, focus on your needs (how much space you need for your programs, games, etc.) and financial capabilities. It is not advisable to use an SSD for data storage; for this you need a more capacious and cheaper hard drive (HDD) with a capacity of 1-4 TB (1000-4000 GB).

4. SSD read/write speed

The main indicators of SSD disk speed are read speed, write speed and access time.

According to statistics, the number of read operations on ordinary user computers is 20 times greater than the number of write operations. Therefore, for us, reading speed is a much more important characteristic.

The read speed of most modern SSDs is in the range of 450-550 MB/s (megabytes per second). The higher this value, the better, but 450 MB/s is, in principle, quite enough, and taking an SSD with a lower read speed is not advisable, since the difference in price will be insignificant. But you shouldn’t blindly trust representatives of budget brands, since the speed of cheap SSDs can drop significantly as the disk space fills up. The speed of a particular SSD drive model in real conditions can be found out from tests on the Internet.

The write speed of most SSDs ranges from 350-550 MB/s. Again, the faster the better, this is understandable. But due to the fact that write operations are performed 20 times less frequently than read operations, this indicator is not so critical and the difference will not be very noticeable for most users. But the price of discs with higher write speeds will be noticeably higher. Therefore, you can take 350 MB/s as the minimum recording speed. Purchasing an SSD with an even lower write speed will not bring significant savings, so it is not advisable. Please note that some manufacturers indicate the write speed for the entire line of SSD drives, which have different capacities. For example, Transcend has drives ranging from 32 to 1024 GB in its SSD370S line. The recording speed for the entire line is 460 MB/s. But in fact, only models with a capacity of 512 and 1024 GB have such speed. The photo below shows a fragment of a Transcend SSD370S packaging with a capacity of 256 GB with a real write speed of 370 MB/s.

Access time determines how quickly the disk finds the required file after receiving a request from a program or operating system. For conventional hard drives, this indicator is in the range of 10-19 ms (milliseconds) and significantly affects the responsiveness of the system and the speed of copying small files. SSD drives, due to the absence of moving parts, have access speeds 100 times higher. Therefore, this parameter is usually not focused on; any SSD provides incredibly high access speeds. However, higher quality models can have an access time of about 0.1 ms, and the most budget ones 0.4 ms. The difference in access time by a factor of 4 is not in favor of budget SSDs. With this parameter, manufacturers of budget SSDs can also be disingenuous and indicate a theoretical value under ideal conditions.

The real speed characteristics of SSD drives can be found out from tests on the most authoritative technical portals. You can download a file with links to them at the end of the article in the “” section.

5. Memory types and SSD resource

Modern SSD drives use several types of memory - MLC, TLC and 3D NAND (V-NAND).

MLC is the most popular type of memory for SSD drives with an optimal price/speed/durability ratio and an estimated resource of 3000-5000 rewrite cycles.

TLC is a cheaper type of memory, found in budget SSDs, with a rewriting resource of about 1000 cycles.

3D NAND is a modern fast memory developed by Samsung with the longest rewriting resource. Installed in more expensive Samsung SSD models.

There is a myth that SSD drives wear out very quickly. Therefore, you need to choose models with the maximum possible resource and use all sorts of tricks in the operating system settings to extend the life of the SSD drive, otherwise it will quickly exhaust its resource and fail.

In fact, the resource of modern SSDs matters only when installing them in servers, where the disks work for wear and tear around the clock. In such conditions, due to the colossal number of rewrite cycles, SSDs actually last an order of magnitude less than their older brothers - mechanical hard drives. But you and I already know that in the computers of ordinary users, the number of write operations, which cause wear and tear, is 20 times lower than read operations. Therefore, even with a relatively heavy load, the resource of any modern SSD will allow it to last 10 years or more.

Despite the fact that data on rapid wear and tear are highly exaggerated, you should not purchase an SSD based on the cheapest TLC memory, since the savings will be insignificant. Today, the best option would be an SSD drive with MLC memory. And the actual service life of an SSD disk will depend more on the quality of production and. Pay more attention to the brand and warranty period.

6. Clipboard

A clipboard (cache) based on DDR3 memory speeds up the operation of an SSD drive, but makes it somewhat more expensive. For every 1 GB of SSD capacity there should be 1 MB of DDR3 cache. Thus, an SSD with a capacity of 120-128 GB should have 128 MB DDR3, 240-256 GB - 256 MB DDR3, 500-512 GB - 512 MB DDR3, 960-1024 GB - 1024 MB DDR3.

Some models have a cache based on older DDR2 memory, but this does not significantly affect performance.

7. Blackout protection

It is desirable that a disk with DDR3 cache memory have protection against sudden power outages (Power Protection), which is usually based on tantalum capacitors and allows you to save data from the buffer to the memory chips in the event of a power failure on the SSD. But if you have an uninterruptible power supply (UPS, UPS), then blackout protection can be neglected.

SSDs that do not have a cache based on DDR3 memory do not require additional protection against power loss.

8. SSD controllers

There are many controllers for SSD drives. The most popular brands include Intel, Samsung, Marvell, SandForce, Phison, JMicron, Silicon Motion, Indilinx (OCZ, Toshiba).

The best SSD drives are built on controllers from Intel, Samsung, and Marvell. In the middle class, the long-proven SandForce and younger Phison controllers are more popular. Inexpensive SSD models are often content with old budget JMicron controllers and younger Silicon Motion controllers. Indilinx produced fairly reliable controllers and was bought by OCZ and then Toshiba for use in their mid-range SSDs.

But each manufacturer has both cheaper and more expensive controllers. Therefore, you need to navigate by a specific controller model, a review of which can easily be found on the Internet.

Most controllers in entry-level and mid-range SSDs are 4-channel. Top SSD models are equipped with faster and more modern 8-channel controllers. But don’t bother too much with controller models, it’s not always easy to figure it out. Focus primarily on the brand, the stated characteristics of the SSD drive and real tests of a specific model, which often also consider the advantages and disadvantages of the installed controller and other electronic components of the SSD.

In addition to the read/write speed, the controller also depends on support for various technologies designed to improve the performance of the SSD drive.

9. Supported technologies and TRIM function

An SSD drive, depending on the model and the controller installed in it, can support various technologies designed to improve its performance. Many manufacturers develop their own proprietary technologies that provide more marketing benefits than actual benefits to users. I will not list them; this information is in the descriptions of specific models.

The most important feature that should be supported by any modern SSD is TRIM (garbage collection). Her job is as follows. An SSD drive can only write data to free memory cells. As long as there are enough free cells, the SSD disk writes data to them. As soon as there are few free cells, the SSD disk needs to clear cells from which data is no longer needed (the file has been deleted). An SSD without TRIM support clears these cells immediately before writing new data, which significantly increases the time of write operations. It turns out that as the disk fills up, the recording speed degrades. An SSD with TRIM support, having received a notification from the operating system about the deletion of data, also marks the cells in which they were as unused, but clears them not before writing new data, but in advance in free time (when the disk is not used very actively). This is called garbage collection. As a result, the recording speed is always maintained at the highest possible level.

10. Hidden SSD area

Each SSD drive has a fairly large amount of memory in a hidden (inaccessible to the user) area. These cells are used to replace those that fail, so that disk space is not lost over time and the safety of data that is previously transferred by the disk from “sick” cells to “healthy” ones is ensured.

In high-quality SSDs, this hidden volume can reach 30% of the declared disk volume. Some manufacturers, in order to save money and gain a competitive advantage, make the hidden disk space smaller (up to 10%), and the amount available to the user is larger. Thanks to this, the user gets more available volume for the same money.

But this trick of manufacturers also has another negative side. The fact is that the hidden area is used not only as an untouchable reserve, but also for the operation of the TRIM function. Too small a volume of the hidden area leads to a lack of memory required for background data transfer (garbage cleaning) and the speed of the SSD disk at high capacity (80-90%) degrades greatly, sometimes several times. This is the price of “free” additional space and this is why high-quality SSD drives have a large hidden area.

The TRIM function must be supported by the operating system. All versions starting from Windows 7 support the TRIM function.

11. SSD manufacturers

The best manufacturer of SSD drives is Intel, but their cost is very high and they are used mainly in the corporate sector for critical systems and servers.

The next leader in terms of technology is Samsung. Their SSDs cost on average higher than all others, but are distinguished by impeccable quality, reliability and speed.

SSD brands Crucial, Plextor (Samsung brand) and SanDisk are recognized as the best in terms of price/quality ratio.

Also, as a compromise option in terms of price/quality, you can consider SSDs from the reputable brands Corsair and A-DATA.

I do not recommend purchasing SSDs sold under the Kingston brand, since most of them do not meet the stated characteristics and their speed greatly degrades as they fill up. But this manufacturer also has SSDs from the top-end HyperX series, which are of higher quality and can be considered as an alternative to top-end expensive brands.

In general, budget and unpopular brands are like a lottery, maybe you’ll get lucky, maybe not. Therefore, I recommend that you avoid purchasing them if possible. But it’s still better to look for reviews on models from recommended brands, since “even an old woman can get screwed.” Let me remind you that links to reviews of SSD drives are in the file that can be downloaded in the “” section.

12. Form factor and SSD interface

The most popular today are SSDs of the 2.5″ form factor with a SATA3 (6 Gb/s) interface connector.

This SSD can be installed in a computer or laptop. The motherboard or laptop must have a SATA3 (6 Gb/s) or SATA2 (3 Gb/s) connector. Correct operation when connected to the first version of SATA connector (1.5 Gbit/s) is possible, but not guaranteed.

When connected to a SATA2 connector, the SSD read/write speed will be limited to around 280 MB/s. But you will still get a significant performance boost over a regular hard drive (HDD).

Plus, the access time will not go away, which is 100 times lower than that of an HDD, which will also significantly increase the responsiveness of the system and programs.

A more compact SSD form factor is mSATA, which is based on the SATA bus but has a different connector.

The use of such an SSD is justified in ultra-compact computers, laptops and mobile devices (tablets) with an mSATA connector, in which installing a conventional SSD is impossible or undesirable.

Another smaller SSD form factor is M.2. This connector replaces mSATA, but is based on the faster PCI-E bus.

The motherboard, laptop or mobile device (tablet) must also have the appropriate connector.

Well, another type of SSD is presented in the form of a PCI-E expansion card.

Such SSDs have very high speeds (3-10 times faster than SSDs with a SATA3 interface), but are significantly more expensive and are therefore used mainly in very demanding professional tasks.

13. Housing material

The SSD case is usually made of plastic or aluminum. It is believed that aluminum is better because it has higher thermal conductivity. But since the SSD does not heat up significantly at all, this does not matter much and may not be taken into account when choosing a model.

14. Equipment

If you are purchasing an SSD for a computer and the case does not have mounts for 2.5″ drives, then pay attention to the presence of a mounting frame in the kit.

Most SSDs do not come with a mounting frame or even screws. But the mount with screws included can be purchased separately.

The presence of a mount should not be a significant criterion when choosing an SSD, but sometimes a higher-quality SSD complete with a mount can be purchased for the same money as a budget SSD with a separate mount.

15. Setting up filters in the online store

1. Go to the “SSD drives” section on the seller’s website.
2. Choose recommended manufacturers (Crucial, Plextor, Samsung, SanDisk), you can also consider Corsair and A-DATA.
3. Select the desired volume (120-128, 240-256 GB).
4. Sort the selection by price.
5. Browse SSDs starting with the cheaper ones.
6. Choose several models suitable for price and speed (from 450/350 Mb/s).
7. Look for their reviews online and buy the best model.

Thus, you will receive an SSD disk that is optimal in size and speed, meeting high quality criteria, at the lowest possible cost.

16. Links

SSD Samsung MZ-76E250BW
SSD A-Data Ultimate SU650 240GB
SSD A-Data Ultimate SU650 120GB

They are the most modern and high-performance data storage for computer systems. They offer much higher data transfer speeds than traditional hard drives, while consuming less power and having higher levels of reliability due to the absence of moving parts in the design of the device.

The characteristics and performance of different SSD models on the market can vary quite a lot, so it is very important to learn as much as possible about solid-state drives before going to the store to buy a device.

In this article, we'll look at some key features and how they can impact the performance and cost of SSD drives—simple, affordable, and straightforward. I really hope that this knowledge will help you when choosing an SSD for your computer.

Volume

SSD is not the cheapest pleasure, and the cost of the device increases in direct proportion to its volume. A good drive with a capacity of 480-512 GB will cost about $200, and a “terabyte” drive will cost about $500.

In order to save on unnecessary waste, savvy users came up with an elementary solution - use an SSD drive to operate the system, and leave a classic hard drive - HDD - for movies, music, photos and other content that takes up the lion's share of disk space.

Thus, it turns out that a bootable SSD disk will ensure faster operation of the system, programs and computer games. And the second disk, HDD, will serve as a kind of storage for the remaining data.

But what size SSD should you choose? Here are my thoughts on this matter:

• 32 GB: with a stretch, it’s suitable for installing an operating system (hereinafter simply referred to as OS) and some low-demanding programs. Suitable for office work, where they do not use anything other than Word and Excel;
• 64 GB: good for installing the OS and most of the software necessary for work. Again, an office version of the drive;
• 120 GB: great for installing the OS and necessary programs. You can even install a couple of your favorite games to load the latest ones faster;
• 240 GB: great for installing OS, software and games. Most likely, you won’t have problems with low memory for a long time, unless, of course, you start cluttering the disk with various multimedia files, such as music and movies. I repeat, for these purposes it is better to use a second disk - HDD;
• 480+ GB: great for installing OS, software, games, and you can even get a little naughty and throw multimedia onto the disk.

This is roughly how I see SSD volumes for the various purposes you are pursuing. The golden mean is, of course, a 240 GB drive. Unless you're an avid gamer who plays another game every week, then it's worth considering better options.

Flash memory

Flash memory is another very important parameter that determines the cost of the device, as well as its performance, read speed and durability. And here, in most cases, the choice is between flash memory with two-bit cells - MLC and three-bit cells - TLC, but which type of memory to choose depends on the tasks for which the SSD is purchased.

If you take an SSD as data storage, then you can safely buy a drive with TLC flash memory. Such SSDs, at the same cost, will have much more memory than MLC SSDs, but have fewer rewrite cycles.

Accordingly, if you take an SSD to install the system, then it is better to choose MLC. The volume will be smaller, but the number of rewrite cycles will be greater. And since the data on the system disk is constantly updated, MLC is an ideal option for a boot disk with the system.

There is also 3D V-NAND flash memory, developed by SAMSUNG. The principle of operation is the same as MLC and TLC memory, only in a three-dimensional model. The 32-layer design is promoted by SAMSUNG under the marketing name V-NAND, and MLC V-NAND and TLC V-NAND flash memory is considered more reliable than its classic counterparts.

Interface

If you choose an SSD for permanent use in a computer or laptop, the connection interface will most likely be Serial ATA (SATA), rather than USB or PCI Express. Why? Because USB is an order of magnitude slower than SATA, and is only suitable as an external drive, and PCIe is an order of magnitude more expensive than SATA, although it is an order of magnitude faster.

Therefore, if you want to get the “golden mean” in the form of excellent speed and not very high price, then you will need a “SATA III” interface with a bandwidth of 6 Gbit/s.

The older "SATA I" and "SATA II" interfaces still have excellent performance, especially when compared to hard drives, but they won't give you the best performance.

On the other hand, you may have to purchase an SSD with a first or second generation SATA interface if your PC is quite outdated and the motherboard only has SATA connectors of the first or second revision. Although, from a technical point of view, you can take the “three”, since the SATA III interface is backward compatible and will work with previous versions.

To check which SATA version you have, you need to Google the model of your motherboard and look at the specifications on the manufacturer's website. You can find out the motherboard model by looking at the name on the board itself or using standard Windows tools. To do this, open the command line (WIN+R -> CMD) and enter the command “wmic baseboard get product” (without quotes).

By the way, interface speeds are measured in gigabits per second, while disk read and write times are measured in megabytes per second. To determine interface restrictions, I have listed the converted values ​​for different SATA versions:

• SATA III (6 Gb/s): 750 MB/s;
• SATA II (3Gbps): 375 MB/s;
• SATA I (1.5 Gbps): 187.5 MB/s.

Remember that this is the theoretical maximum throughput for the various SATA interface standards. Real performance will be slightly lower than these figures. For example, most SATA III SSDs peak between 500 and 600 MB/s, which is about 20-30% below the maximum.

Read/write speed

Read Speed ​​- Determines how long it takes to open or read a file stored on disk.

Write speed is how long it takes to save or write to disk.

These parameters are one of the most important technical characteristics in solid-state drives, essentially showing the performance of the SSD. High read speed makes loading programs and games faster (as well as the entire operating system as a whole), and write speed affects tasks such as unpacking files using 7Zip.

Most modern SSDs have read speeds in the range of 500-600 MB/s, but very cheap/old SSDs cannot boast of such speeds. Therefore, I would advise choosing an SSD with a read speed in this range.

If you compare HDDs and solid-state drives, you can see that hard drives are several times slower than SSDs, with a read speed of 128 MB/s and a write speed of 120 MB/s. It is for this reason that when you “switch” from HDD to SSD, you will immediately feel an incredible increase in system loading speed when you turn on the computer, however, as mentioned a little above, you will also notice an increase in speed in loading games, opening programs, saving files and so on.

I would like to note that the write speed is not as important as the read speed, and therefore you can sacrifice a weak characteristic for the sake of a stronger parameter if the disk has a good read speed, but a much lower write speed.

Form factor

The form factor determines the size of the footprint and mounting for the drive. In most system units, space for a disk drive is made in a 3.5’’ form factor. This is where your computer's hard drive is most likely installed.

Since manufacturers are gradually abandoning the 3.5'' form factor, the vast majority of SSD drives are made in the 2.5'' form factor. But don’t be scared or stress yourself out, because if it comes to a personal computer, then you can easily install a brand new SSD in the system unit instead of a 3.5’’ HDD or next to it. To do this, you just need to purchase a special mounting frame (or an adapter, in other words), by placing a 2.5’’-inch SSD in it, you can easily install the latter in a 3.5’’ form factor mount.

But if you really can’t bear it, or purchasing a mounting frame is a problem, then you can screw a 2.5’’ solid-state drive onto two out of four bolts. One of my friends did exactly this and is happy as an elephant :)

If you're planning to install an SSD in your laptop to replace the hard drive, you'll also want to be aware of the physical size limitations. For example, 2.5-inch rims are typically available in several height ranges, from as thin as 5mm to taller ones as high as 9.5mm.

If your laptop can only fit a drive with a height of up to 7.5 mm, and you buy a 9.5 mm SSD, then, of course, this drive will not work. The same applies to mSATA and M.2 drives, used exclusively in laptops, ultrabooks and hybrid systems.

Therefore, be careful.

Manufacturer

An SSD is quite a large investment (by the standards of PC components), and if you decide to buy, it is better to do it from a quality, trusted brand. An excellent choice would be:

• Samsung is ahead of the curve in the development, production and sale of solid-state drives, winning 44% of the market for these devices. And there is nothing surprising here, because the company develops SSDs from start to finish, which together gives stable operation of the device and technical progress in this direction that is ahead of many manufacturers;
• Kingstone - the company does not develop devices at all stages, but works very competently with third-party manufacturers. The products of this brand offer market consumers a fairly flexible choice of high-quality SSD drive models, which has enabled Kingstone to gain a good foothold in the market of this segment;
• Crucial (Micron) and SanDisk are excellent choices as they offer high-quality, reliable products that operate at good speeds.

Buying an SSD from a “no-name” manufacturer is a rather risky step, especially if the price of the product is suspiciously low compared to similar drives from competitors. Using such a product, you can get seriously burned if something happens to the system or personal data.

Copyright "P.S.:"

We'll probably end here. Of course, one could name a dozen more different parameters that would give some flexibility in the question of which SSD to choose, but I believe that I have already outlined the most important thing in this article, and everything else is quite secondary characteristics that are clear to the average user They won’t contribute, but will only create, as they say, a mess in the head.

Happy shopping, thanks for reading to the end! Hope you liked it ;)

One of the most frequently asked questions by users is “which SSD should I buy?” Indeed, there are many models on the market from different manufacturers and you really want to make the right choice. In this short note, we will tell you what you should pay attention to when buying an SSD drive and give recommendations on choosing specific models.

The main thing is the guarantee.

Since ssd drives are still not the cheapest pleasure (compared to regular hard drives in the first place), we recommend that when purchasing, pay first attention to the warranty period. The longer the seller gives a guarantee, the better. However, there is an important feature in this matter. Very often, buyers confuse the warranty period of the manufacturer and the seller. For example, the following statements are common: “XXX company gives a 5-year warranty, and the seller only a year, but we know the laws of Russia, according to the law, the seller cannot give less than the manufacturer, so the warranty will be 5 years.” About the laws - correct, but “there is a nuance.” It often happens that the disk manufacturer does not have an official representative office in Russia or does have one, but it deals not with ssd disks, but with other products of the concern. Therefore, ssd drives from such a manufacturer often end up through “gray” channels, and in this case the law does not work and you can only rely on the warranty period provided by the seller.

The difference in speed is noticeable only in rare applications

The natural desire of all buyers is to have the “fastest disk,” but keep in mind that if you choose an ssd disk as the main (system) disk in a computer (laptop) or a second disk for your data - photos, videos - then all modern ssds are more than fast for your tasks. The difference in the speed of their operation will be completely unnoticeable; rather, problems may arise due to a lack of RAM or a slow processor.

256GB is faster than 128GB.

Another feature inherent in ssd drives is the dependence of operating speed on the size of the hard drive. We will not go into technical details (if you wish, you can read about it here), briefly - 64GB works slower than 128GB, and it, in turn, is slower than 256GB (further increasing the volume does not give much of an increase in speed). In addition, the larger the disk capacity, the larger its reserve area, and therefore its reliability. Therefore, we recommend 128GB as the minimum starting size for an SSD drive.

“Enough theory and explanations, name is sister, name! “Can you name specific models that you recommend for purchase,” you say. Well, let's give some recommendations based on our subjective taste.

1. The fastest SSD drive, money doesn't matter. Samsung 850 Pro
2. Compromise between speed and price. Samsung 850 EVO
3. Low price, but tolerable performance. Samsung 840 EVO
4. Low performance and low price Crucial MX100 This is a special category. We cannot recommend these ssd drives even as main (system) drives, but on the other hand, they are still much faster than hard drives and can be considered for storing large amounts of personal data - photos, videos, of course, subject to a low price. If you are still using an HDD hard drive as a system drive, then even these drives will give you a huge speed increase.

Of course, remember that your region may have its own pricing peculiarities in stores and it may well be that the disc from point 4 will be more expensive than the disc from point 3. You shouldn’t be surprised at this, there are different cases. But in this case it’s really necessary to buy the disc from step 3 :) And don’t forget about the warranty. Let's give a brief summary:

Which SSD drive to choose?

1. Choose an SSD drive with the longest warranty period from the seller.

2. 128GB is good, but 256GB is even better. 64GB only as a last resort.

3. The most affordable - Crucial MX100, Samsung 840 EVO, price/speed compromise - Samsung 850 EVO, best speed - Samsung 850 Pro

Note: all these recommendations apply to normal, “home” or office use of a computer; in the case of specialized tasks (servers, databases, etc.), other rules apply, other SSDs apply, and we will talk about them in another article.

In recent years, the cost of SSD drives has dropped significantly and today, in 2017, you can buy a good SSD for less than $100. Of course, this will be a modest capacity, 120 or 128 gigabytes, but it is quite enough for a system drive. So, it is already possible and even necessary to switch from old mechanical to new electronic disks.

Why you need to use SSD drives

Advantages of SSD drives over old HDDs:

• Less electricity consumption.
• Less heat generation.
• No noise because there are no moving mechanical parts.
• Higher reliability due to the absence of moving mechanical parts.
• But the most important thing is several times higher writing and reading speeds. The best SSD models have read and write speeds that exceed even the throughput of the SATA III standard, which is approximately 570 MB per second. That is, the speed of the best SSD drives is higher than the speed of the SATA interface. For HDD speed limits are 130 - 140 MB per second.

Higher writing and reading speeds are the most important advantage of SSD drives, because it is the speed of the drives that has always been the bottleneck in the overall speed of a computer. Relatively speaking, if the disk can work three times faster, then the computer will work twice as fast. Moreover, using an SSD can give speeds even higher than the limit of the SATA interface. Since these are electronic disks and are essentially just boards with microcircuits, they can be made, for example, with a PCI-express interface, and this already provides speeds of more than a gigabyte per second.

For some time, at the beginning of the production of SSD drives, there was a problem with their short life (short compared to HDDs). But today, good models from the best manufacturers can work for years. It is not uncommon for a manufacturer's warranty on these discs to last 5 or even 10 years. So, the only argument against SSDs today is the higher price for 1 GB of capacity. One gigabyte of SSD capacity still costs six times more than HDD. However, this problem can be solved in the following way - use HDD to store large files (videos, etc.), and SSD for the system and programs.

How to choose a good SSD

Now let's move on to the topic of the article. When choosing an SSD, you need to look at two main characteristics - speed and reliability. Speed ​​depends on the components (memory and controller) used in the drive. And reliability depends on the components (memory type) and the manufacturer. Further, this article will discuss in detail all the primary and secondary characteristics of electronic disks.

Characteristics of SSD drives

This part of the article will describe the most significant characteristics of SSD drives. Technical parameters that improve or worsen the consumer quality of SSD drives.

Main characteristics of SSD

These are the SSD parameters that most affect the consumer quality of the drives.

Manufacturer

SSD drives are made by many companies. Even more companies sell them under their own labels without manufacturing them (OEM production). But there are only a few companies whose discs are safe and secure to buy.

• Intel. The company, together with Micron, produces flash memory. Thus, it makes its own disks from its own memory and selects the best memory copies for its disks. It is no coincidence that they provide a 5-year warranty on their discs.
• Micron(trademark Crucial). The company produces flash memory together with Intel. Thus, it makes its own disks from its own memory and selects the best memory copies for its disks. The difference from Intel is that Micron (Crucial) focuses on the budget segment of the market. Lower price, shorter warranty period. But the wheels are good.
• Samsung. One of the leaders in the SSD market. And not only in terms of sales volume, but also technologically. The company produces its own flash memory and its own controllers. The disks are 100% proprietary - both memory and controllers, everything is our own.
• Plextor. A Japanese company famous for its laser drives. In fact, the SSD is not made by itself - Lite-On makes them for it. But the discs are very good.
• Corsair. An American company known for the high quality of various products - RAM, power supplies. The company's products are aimed at so-called "enthusiasts", people willing to pay more for higher quality and speed.
• SanDisk. An American company, one of the leaders in the production of flash drives and SSD drives. Partner of Toshiba in the production of flash memory chips. Thus, disks are made from its own flash memory.
• Toshiba. The Japanese company is, among other things, a manufacturer of flash memory chips. Thus, disks are made from its own flash memory.

SSD disk capacity

SSD drive manufacturers indicate this difference in the specifications of their drive models. Therefore, before buying a fast drive, carefully read its specifications; perhaps the size you have your eye on is not as fast as you expect.

That's when size matters.

There is one more feature related to the capacity of SSD drives. There are groups of models based on capacity, but not all models in this group have the same capacity. Example. Group with a capacity of 120/128 GB. Some models in this group have a capacity of 120 GB, while others have a capacity of 128 GB. What is this connected with?

The fact is that in fact all disks in this group have a capacity of 128 GB, but on some models 8 GB is reserved both to level out the wear of flash memory cells and to replace failed cells.

Some manufacturers may not be entirely sure of the quality and lifespan of the flash memory used in their model and therefore make such a reserve. Some people make such a reserve simply for greater reliability. For example, the quality of flash memory in Intel drives is very high, however, the company is playing it safe by making a reserve of cells.

Controller used in the disk

The best controllers are considered Marvell 88SS9187, Samsung MDX. More details about controllers later in this article.

Write speed degradation (garbage collection)

Reduced writing speed on an SSD disk after it is completely full and data will be deleted after filling. That is, writing to reusable memory blocks. Read more about this in the section.

Minor SSD Features

Hardware encryption with support for TCG Opal 2.0 and IEEE-1667 standards. This makes it possible to use hardware encryption but manage it from the OS. For example, it will be possible to offload the central processor when using Windows BitLocker.

Power Loss Protection. Some SSD drive models have protection against sudden power failure. Usually these are just capacitors, the charge of which is enough for the disk to complete the necessary write operations to the memory cells.

Interfaces

This part of the article describes the interfaces through which SSD drives are connected to a computer.

SATA

Today (2016) all SSD drives are available with a SATA 3 interface. However, there are still many computers with SATA 2 (SATA 300) and even SATA 1 (SATA 150) controllers installed on their motherboards. Is it possible to install a new SSD drive in such a computer?

Of course you can. However, you need to understand that in this case the new SSD drive will produce real speed significantly lower than its rated characteristics.

Modern SSD drives can typically perform read operations at speeds of over 500 MB per second. And recording speeds are more than 400 MB per second. This speed can be fully realized on computers with a SATA 3 controller (SATA 600), for which the practical data transfer speed limit is approximately 570 MB per second.

But for SATA 2 controllers, practical speed is limited to approximately 270 MB per second. Accordingly, for SATA 1 controllers it is even lower - less than 150 MB per second. So, if you put a new SSD drive into an old computer, it will run slower than it can.

So for a new SSD drive you need to buy a new computer? No.

There are other options to get full speed on your old computer. You can install a SATA 3 controller made on a PCI or PCI-express board. And then connect the SSD drive through this controller.

PCI-express

In addition, there are now models of SSD drives that are made in the form of a PCI-express card, for example Plextor M6e. So you don’t need to buy anything else, just insert the disk card into the PCI-e slot and that’s it. You can also install an M.2 form factor SSD into the PCI-e slot, but through an adapter card from M.2 to PCI-e.

M.2 (Next Generation Form Factor, NGFF)

Also, a new, faster interface for peripheral devices has now been approved - M.2. You can buy an M.2 adapter made on a PCI-express board and then install an SSD drive with an M.2 interface there. The disk mentioned above Plextor M6e, just such an option is a PCI-express card with an M.2 adapter, on which a disk with an M.2 interface is installed.

The new M.2 interface (Next Generation Form Factor, NGFF) is essentially a PCI-express bus, only the connector has been changed - it is adapted not for expansion cards, but for small devices. SSD drives in the M.2 form factor are already on sale. This interface should provide data transfer speeds higher than the practical limit for SATA 3 - 570 MB per second. The M.2 interface specification assumes the use of 4 PCI-express lines. For SSD drives in the M.2 form factor, 2 PCI-express lanes are used so that theoretically the exchange speed with the drive can reach 2 GB per second.

Memory

There are two types of flash memory (flash-memory) - NAND and NOR.

The difference between NAND memory and NOR is that the cells are combined into blocks and processed in blocks. While in NOR, each cell is processed individually. NAND memory has longer access times to memory cells, but is significantly cheaper to manufacture.

In the production of SSD drives, NAND type flash memory is used.

NAND flash memory manufacturers

Memory for SSD drives is manufactured by only a few companies - Intel and Micron (general production), Toshiba and SanDisk (general production), Samsung, Hynix.

The first such memory was created by Toshiba in the late 80s of the last century. Thus, it is the oldest NAND flash manufacturer. Based on the type of pin layout in the chip package and subsequent access from the controller, NAND flash is divided into two types:

• Synchronous and asynchronous ONFI. It is manufactured by Intel and Micron, Hynix
• Asynchronous Toggle Mode. It is made by Samsung, Toshiba and SanDisk.

Types of NAND Flash Memory Cells

Today (in 2016) SSD drives use NAND flash memory with three types of cells:

• NAND SLC(single-level cell) - flash memory in one physical cell which stores one bit of information.
• NAND MLC(multi-level cell) - flash memory in one physical cell which stores two bits of information.
• NAND TLC(triple level cell) - flash memory in one physical cell which stores three bits of information.

The difference between these types is that as the number of bits stored in one cell increases, the cost of memory in terms of its capacity decreases. That is, relatively speaking, 128 GB of MLC memory is cheaper than the same 128 GB, but of the SLC type. And 128 GB of TLC memory is cheaper than the same amount of MLC.

However, you have to pay for everything. As the number of bits per cell increases, the number of write cycles that cell can withstand decreases. For example, SLC type memory can withstand up to 5000 - 10,000 rewrite cycles. And the writing limit for MLC memory is up to 3000 cycles. For TLC type memory this limit is even lower - 1000 write cycles.

That is, as the number of bits per cell increases, the lifetime of this cell decreases.

Basic parameters of flash memory for SSD

The main characteristics of flash memory for SSD drives are:

1. The number of write cycles that a single cell of this memory can withstand. This parameter determines the lifespan and reliability of flash memory.
2. The technical process by which the flash memory crystal is manufactured.
3. Type of flash memory cells.

The second and third flash memory parameters directly affect the first parameter. The dependency is as follows:

• Reducing the process technology reduces the lifespan of flash memory.
• Increasing the number of bits per cell reduces the lifetime of flash memory.

That is, MLC type memory will have a shorter lifespan than SLC type memory. Memory manufactured using a 25-nanometer process will have a longer lifespan than one manufactured using a 19-nanometer process.

Memory capacity (size)

Indicated in gigabytes. The peculiarity of SSDs is that larger capacity disks provide faster data exchange speeds, especially when recording. The difference in writing speed between a 120/128 GB disk and a 480/512 GB disk can be up to two or three times.

For example, a disk with a capacity of 120/128 GB can give a maximum recording speed of less than 200 MB per second, and a disk of the same model, but with a capacity of 480/512 GB will give a writing speed of more than 400 MB per second.

This difference is due to the fact that the SSD disk controller works with all memory crystals simultaneously (in parallel). And one disk model uses the same memory crystals. Accordingly, the difference in capacity is the difference in the number of crystals. Fewer memory crystals means less parallelization of operations and lower speed.

There is no need to confuse memory crystals and memory chips. One chip can have from one to four memory crystals. That is, in disks of different capacities the number of microcircuits may be the same - 8, but the number of crystals will be different.

Manufacturers of SSD drives indicate this difference in write speed in the specifications of their drive models. Therefore, before buying a fast drive, carefully read its specifications; perhaps the size you have your eye on is not as fast as you expect.

It happens that a person reads a test review on the Internet, which says that the XX disk gives a write speed of 450 MB per second. And buys this disk model. Installs and is surprised to discover that the write speed is only 200 MB per second. The thing is that he read about a model with a capacity of 512 GB, but bought a model with a capacity of 128 GB.

This difference increases as new 128-bit memory crystals enter the market, instead of 64-bit ones. Simply put, if an SSD is assembled on 64-bit memory chips, then full speed of read/write operations is possible on disks with a capacity of 240/256 GB. And if the disk is assembled on 128-bit memory chips, then the full speed of read/write operations is only possible on 480/512 GB disks.

For example SSD drive Crucial M500 assembled on 128-bit memory chips. There are 4 models in this line:

• 120 GB - write speed 130 MB per second.
• 240 GB - write speed 250 MB per second.
• 480 GB and 960 GB - write speed 400 MB per second.

As you can see, the difference in recording speed between the younger and older models is more than three times. Although these are the same discs in all respects. Except for the number of memory crystals. By the way, Crucial in its 2014 model M550 uses crystals of different bit depths. For 128 and 256 GB models, 64-bit crystals are used. For 512 GB and 1 TB models, 128-bit crystals are used. Due to this, the difference in speed between the younger and older models has been reduced.

There is one more aspect depending on the disk capacity. The larger the disk capacity, the theoretically longer its service life. The fact is that a flash memory cell can withstand a limited number of write cycles and when this limit is reached, for example, an MLC type cell has been written to 3000 times, it fails.

All SSD disk controllers use cell interleaving during recording in order to even out cell wear. Free memory is used for interleaving. Accordingly, the less the disk is occupied with data and programs, the more opportunities the controller has for interleaving cells and the longer the memory will last.

Large disk capacity is the easiest way to increase free disk space. Let's assume that your programs and data occupy 100 gigabytes. If this is placed on a 120 or 128 GB disk, then the disk will be almost entirely occupied and few cells will be available for striping. But if the disk capacity is 240 or 256 GB, then a lot of cells will be available for striping - more than 50%. Thus, the load on the cells will be much lower and there will be longer and more even wear.

Controllers

The computer cannot gain direct access to flash memory, so in addition to memory chips, a controller chip is also installed in the disks. Several companies produce such microcircuits:

• SandForce. Now this company is owned by another company - LSI. SandForce controllers, such as the SF2881, are the most common. They dominate the budget SSD segment. Even Intel produces SSD drives on these controllers (models 520, 530).
• Marvell- their controllers 88SS9187 and 88SS9174 are used in high-performance SSD drives from different manufacturers, in particular Micron (Crucial), Plextor, SanDisk. For example, some of the fastest SSD drives in the world are Plextor M5 Pro, Crucial M500, Crucial M550, use controllers Marvell88SS9187, 88SS9189.
• Indilinx. Now this company is owned by OCZ and the latest controller model is called Barefoot 3. Accordingly, these controllers are mainly used only in OCZ drives.
• LAMD (Link_A_Media Devices). The fast but rarely used LM87800 controller. For example, it is used in Corsair Neutron drive models. The company was bought by the Korean Hynix and these controllers are used only in conjunction with Hynix flash memory.
• Phison. This company has long been known for its controllers for USB flash drives. Recently, it has begun an attack on the SSD drive market. It offers low-cost solutions for the production of SSD drives - controller, firmware, board design. Its controllers are used in budget models, for example Corsair LS, SmartBuy Ignition 2.
• MDX. This controller was developed by Samsung and is used in its drives.
• Intel. In some models of its SSD drives, Intel uses its own controller. These are server models S3500, S3700, as well as the Intel 730 model aimed at the business segment of the market.
• Silicon Motion. Another company offering budget controllers for SSDs. In terms of performance, nothing outstanding.

Various characteristics of the SSD disk depend on the controller. Speed ​​of operation, lifespan of flash memory, resistance to data corruption.

For example, Marvell controllers provide high performance with operations on arbitrary data blocks. This is exactly the load that falls on the disks in real computer operation. The Intel controller is focused on high performance under conditions of a large number of parallel requests (server load model).

But SandForce controllers have an unpleasant feature - after the disk is full and cleared, the write speed does not return to its original values ​​(when the disks were empty). The speed of operation also decreases when the disk is very full. At the same time, SandForce controllers provide high recording speed on easily compressible data, such as texts and documents.

Each controller has its own characteristics. Your strengths and weaknesses. If you have certain mandatory requirements for an SSD drive, then when choosing a model it makes sense to study the features of the controllers.

Inexpensive SSD drives

Inexpensive SSD drives are usually made on SandForce controllers, and over the last couple of years Silicon Motion and Phison have been actively working in this segment.

The reason for this is that these companies offer complete solutions for manufacturing SSD drives. There is not only a controller, but also the firmware for it, as well as the board design for mounting all the hardware.

Thus, the manufacturer of finished drives does not need to do anything other than solder the parts onto the board and mount the board into the case.

TRIM (garbage collection)

SSD drives have an important difference from HDDs that affects the write speed. In HDD, recording is performed “on top” of old data. Disk blocks that previously contained data and then that data was deleted are simply marked as free. And when you need to write, the HDD controller immediately writes to these free blocks.

When using flash memory, blocks that previously contained some information must be cleared before being written. This leads to the fact that when writing to previously used blocks, the writing speed drops significantly, because the controller needs to prepare them for writing (clear them).

The problem is that operating systems traditionally do not work with the file system in such a way that deleting files clears the contents of the blocks on the disk. After all, there was no need for this on HDDs.

Therefore, when using SSD drives, the effect of “performance degradation” occurs. When the disk is new and all flash memory blocks are clean, the write speed is very high, as specified. But after the disk is completely full and some of the files are deleted, re-writing will occur at a lower speed. Because the disk controller will have to clear the flash memory blocks before writing new data there.

The drop in write speed to reused flash memory blocks can be very high. Up to values ​​close to the recording speed of HDD disks. When testing SSD drives, they often even conduct a special test to reduce the write speed of reusable blocks.

To combat this phenomenon, the new operating systems have added the TRIM disk ATA command. When a file is deleted, the file system driver sends the TRIM command to the SSD disk controller. Using this command, the SSD disk controller clears freed flash memory blocks, but does this in the background, in between read and write operations.

Using this command returns full write speed to reused flash memory blocks. However, not all operating systems support this command. But only relatively recent versions:

• Linux kernel since version 2.6.33.
• Windows 7
• Windows 8
• Mac OS X starting from version 10.6.6 (but for this version you need to install an update).

Until now, the popular WIndows XP (as well as Vista) do not support this command.

A workaround for older OSes is to use third-party programs. For example, this could be the hdparm program (version 9.17 and higher) or proprietary programs of the SSD drive manufacturer, for example Intel SSD Toolbox.

There are two models of SSD drives in which the degradation of the speed of reused blocks is less pronounced than others:

• Plextor M5 pro.
• Plextor M5S.

The firmware of these disks can partially clear unused blocks without the TRIM command. Restoring the write speed to higher values, but not to the full rated write speed.

There are disk models that, even after executing the TRIM command, do not return to the full rated write speed.

The TRIM command may not work if the motherboard's SATA controller was set to IDE mode (for compatibility with an older OS or program).

The TRIM command is most often disabled when using a RAID array.

SSD drives by manufacturer

Personally, I divide all SSD drive manufacturers into two categories - the big seven and all the rest. The Big Seven are Intel, Plextor, Corsair, Samsung, Micron (under the Crucial brand), Toshiba, SanDisk. Companies that sell good and excellent SSD drives. Each of them has its own advantages, for example Intel, Samsung, Toshiba, SanDisk and Micron make drives from their own flash memory. And Samsung uses not only its own memory in its SSD drives, but also its own controllers.

But in principle, you can buy any disc from any of these seven companies without going into details.

Everyone else is a pretty big list.

Intel. The company, together with Micron, produces flash memory. Thus, it makes its own disks from its own memory and selects the best memory copies for its disks. It is no coincidence that they provide a 5-year warranty on their discs. Some models also have their own controllers - that is, 100% Intel - such models as Intel DC S3500, Intel DC S3700, Intel 730. Intel's drives are very good, but the company primarily targets the business segment of the market and therefore its drives are quite expensive.

But her discs are worth the money. For example, server SSD drives DC S3500 and S3700 use not only selected memory, but also functions such as power loss protection and advanced checksum verification for stored data. This makes them very reliable means of storing data.

Micron(trademark Crucial). The company produces flash memory together with Intel. Thus, it makes its own disks from its own memory and selects the best memory copies for its disks. The difference from Intel drives is that Micron (Crucial) focuses on the budget segment of the market. Uses its own memory and Marvell controllers. In 2014, the company releases a disc that could become a new hit (like M4) - Crucial M550.

Samsung. One of the leaders in the SSD market. And not only in terms of sales volume, but also technologically. The company produces its own flash memory and its own controllers. The disks are 100% proprietary - both memory and controllers, everything is our own. As of the first half of 2014, the model Samsung 840 Pro This is the fastest SSD drive in the consumer segment of the market (drives for regular computers). The speed of this drive already exhausts the capabilities of the SATA 3 interface.

Plextor. The Japanese company is famous for its laser drives. In fact, the SSD is not made by itself - Lite-On makes them for it. But the discs are very good. Intel-Micron or Toshiba memory and Marvell controllers are used. Famous model Plextor M5 Pro despite the fact that it is no longer young and in 2014 remains one of the fastest SSD drives.

Corsair. An American company known for the high quality of various products - RAM, power supplies. The company's products are aimed at so-called "enthusiasts", people willing to pay more for higher quality and speed. The company has several model lines - GS and GT disks on the SandForce controller, LS disks on the Phison controller, Neutron disks on the LAMD controller.

SanDisk- it has its own production of flash memory (shared with Toshiba) and some models of SSD drives from this company demonstrate very high performance. The company has a long and successful history of various types of flash drives (USB flash drives, memory cards).

Toshiba- it has its own production of flash memory (common with SanDisk). The company has a long and successful history of producing both flash memory and conventional (HDD) disks.

SSD disk lifespan

The time that an SSD drive will work is generally determined by the type of flash memory. That is, what type of cells is used and what process is used to make the memory. It was already written above that SLC type cells have the largest resource, followed by MLC and finally TLC.

What does the limit on the number of write cycles mean in a practical sense? And how can we roughly estimate the possible lifespan of a particular disk?

Let's take a conventional disk that uses MLC flash memory produced using a 19-nanometer technical process. Let's assume that the manufacturer of this memory specifies a write limit of 3000 cycles for it. This is an indicator for good MLC flash memory manufactured using 19 or 20 nanometer manufacturing processes.

Based on this memory, a disk with a capacity of 120 GB was manufactured. The 3000 cycle limit means you can completely write your disc 3000 times. If you fill it completely every day, then empty it completely and fill it completely again the next day, then theoretically the memory will last 3000 days. That is more than 8 years. If you write only 60 gigabytes per day and erase the disk only once every two days, then the lifespan increases to 16 years.

Of course this is simplified. But it is clear that the lifespan of flash memory is quite long. Even if we take a TLC flash-based disk with a limit of 1000 write cycles, this gives a theoretical disk lifespan of at least 3 years, provided that it is completely filled every day.

That is, in all these complaints about the constantly decreasing recording limit, there is no serious basis.

So you can independently estimate the lifespan of a disk, knowing the type of flash memory that is used in this disk. You can more accurately determine it if you have information about the manufacturer of this memory, because flash memory manufacturers indicate write limits for their products.

Finally, many disk manufacturers, in their disk specifications, explicitly indicate disk write limits in gigabytes per day. For example, Samsung in the specifications of the 840 Pro drive writes: “A 5-year warranty is provided provided that no more than 40 gigabytes are written to the disc per day.” And Micron, for its Crucial M550 drive, specifies a recording limit of 72 terabytes, or approximately 66 gigabytes per day for three years.

However, in 2016, Samsung provides a 10-year warranty on some PRO series models. And for some models of its budget EVO line, it provides a 5-year warranty. This is despite the fact that EVO models use TLC type memory.

How to extend the life of an SSD drive

Free disk space. Don't fill it up completely - try to have 20 - 30 percent free space on the disk. The presence of free space allows the controller to level out the wear of memory cells. It is better if this free space is not allocated, that is, not assigned to any partition with the file system.

Uninterruptible power supply. If you are using an SSD in a regular computer, connect the computer via a UPS. If the SSD is in a laptop, monitor the battery condition - do not allow the laptop to turn off when the battery is completely discharged. SSD drives don't like sudden power loss. If there is an abnormal power outage on the disk, the data in the flash memory cells may be damaged. As an option, you can buy a disk model that has Power Loss Protection.

Refrigerate. SSD drives (like HDDs, like any electronics) do not like overheating. The higher the temperature of the disk, the faster it will fail. If you install an SSD in a laptop, then you can only hope that the designers of your laptop have provided for the possibility of sufficient heat removal from the disk.

But if you install an SSD in a regular computer, then your hands are free. The least you can do is use a metal adapter from 2.5" (SSD drive) to 3.5" (drive box in the case). The metal of the adapter will transfer heat from the disk to the body. However, for drives in a plastic case, a metal adapter is useless.

A big plus is the aluminum SSD case. If the drive is designed correctly, the metal case is used as a heat sink to remove heat from the chips.

In addition, you can install a fan - many cases even provide space for a special fan that blows air over the drive cage. Some cases even have this fan.

High quality power supply. If you install the disk in a desktop computer, use a high-quality power supply. However, this point is relevant not only for extending the life of SSD drives, but also of all computer components in general. By the way, HDD drives also do not like “bad” power.

Don't defragment. File system fragmentation does not reduce the speed of the SSD. Therefore, by doing defragmentation you will not gain speed. However, by defragmenting, you will shorten the life of the disk by increasing write operations.

Installing an SSD on an old motherboard

You can breathe new life into your old computer by replacing the HDD with an SSD. All disk operations will be performed two to three times faster. And the computer performs a lot of disk operations - starting the OS, launching programs, opening files, editing files, etc.

If you have an old motherboard with a SATA 2 (SATA 300) controller, then the new SSD drive will not work at full speed. There are two options to fix the matter:

• Buy a SATA 3 controller on a PCI or PCI-e board.
• Buy an SSD drive mounted on a PCI-e card, for example Plextor M6e.

Although, in my opinion, it’s easier to leave it as is. In real life, the difference in speed between connecting via SATA 2 and via SATA 3 may not be very large. It will only appear in operations that involve reading large amounts of data located sequentially on the disk. And accordingly, when sequentially recording large amounts of data. In practice, usually both writing and reading occur in small amounts in arbitrary (non-sequential) areas of the disk.

However, an SSD drive mounted on a PCI-e board is generally a good idea, since it will work faster than when connected even through a SATA 3 controller.

Common mistakes when using SSD drives

Error one

Moving a large number of files to a regular magnetic disk (HDD). Some people install only the operating system and programs on an SSD drive, and transfer everything else to the HDD drive. Temporary file folders, browser cache folders, documents, and even the entire user profile.

They do this in order to save space on the SSD drive and increase its lifespan by reducing write operations. After all, for example, folders of temporary files and a swap file are permanent write operations.

Yes, and space on the SSD is saved and the lifespan is increased. But this significantly reduces the speed of the computer. After all, the faster the disk reads or writes temporary files, documents, profile files, the faster the work is done.

My categorical opinion is that everything related to the OS and programs should be placed on an SSD drive. Working documents also need to be stored on an SSD drive. It makes sense to store only large amounts of data on the HDD - music, movies, laser disk images, etc. And also data that is very rarely used - archives. Only in this case will you get the highest speed from your SSD drive. Don't forget - the main reason to buy an SSD drive is speed! And that means you need to squeeze this speed to the maximum.

Error two

Disk Defragmenter. Out of habit left over from using HDD drives, people also defragment SSD drives. There is no need to do this! The speed of access to arbitrary data blocks on an SSD disk is approximately two orders of magnitude higher compared to an HDD. Therefore, data fragmentation no longer affects the reading speed of this data.

Summary

Basic parameters of SSD drives

• Manufacturer. The best manufacturers of SSD drives are Intel, Micron (Crucial), Samsung, Plextor, SanDisk, Toshiba, Corsair.
• Disk capacity. The minimum disk size, which provides greater speed and a good supply of free space to extend life, is 240/256 gigabytes. For drives with a capacity of 60 - 128 GB, the write speed will almost certainly be below 200 MB per second. Although there are some models of such disks with a writing speed of more than 200 MB per second.
• Controller. The best controllers today are Marvell, Intel, Samsung.

Secondary parameters of SSD drives

• Memory type. SLC memory “lives” the longest; MLC and TLC, in decreasing order, have a shorter lifespan.
• Memory process technology. Memory crystals created using a 19 or 20 nanometer process have a shorter lifespan than crystals created using a 25 nanometer process.
• Hardware encryption with support for TCG Opal 2.0 and IEEE-1667 standards.
• Power Loss Protection.

Which SSD drive to choose

Something like this:

• Manufacturer: Intel, Samsung, Plextor, Corsair, Micron (Crucial).
• Memory type: NAND Flash MLC or TLC.
• Disk capacity: ranging from 240 - 256 Gigabytes. However, 120-128 GB is also a good option.

For example these models: Intel 730, Intel S3500, Plextor M5 Pro, Crucial M550, Samsung 840 Pro. From these models Samsung 840 Pro And Crucial M550 will give the highest writing and reading speeds to date. A disk Intel S3500 will provide the highest guarantee of data integrity and safety.

Of course, when choosing a disk, you need to take into account the tasks that will be performed on the computer. If this is an ordinary home or office computer on which the main work is the Internet and documents, then the cheapest SSD drive with a capacity of 120/128 GB will do.

If this is a gaming computer, then firstly you need to take a volume of at least 240/256 gigabytes, and secondly, select a high-speed model. Because one game sometimes takes up to ten gigabytes on the disk, and during the launch process and during the game, large amounts of information are read from the disk.

If you have a computer for video processing, you need a capacity of more than 240/256 gigabytes and a model with the highest sequential writing and reading speeds.

If the computer will store and process critical information that cannot be lost, then apparently the best choice would be Intel S3500 or even Intel S3700.

If you plan to use the SSD with an old OS, such as Windows XP, it makes sense to think about the effect of “speed degradation” and how to avoid it (more details in the section).

Update 2016

In rubles, SSDs have become more expensive and plus the general crisis is bad news.

The good news is that there are SSD drives with a 10-year warranty - these are some Samsung 850 Pro series models. And Intel even gives a 5-year warranty for its budget 535 series. Despite the fact that the smallest disks (120 GB) from these companies already cost around $100.

Prices (in dollars) go down, productivity goes up.

Another good news applies to TLC memory drives. Such disks can have a lifespan comparable to disks based on MLC memory.

This became possible thanks to the development of a new algorithm for removing signals from memory cells - LDPC decoding. Today (in 2016) there are three controllers that support this algorithm:

• Samsung MGX, SSD drives Samsung EVO 750 and 850.
• Marvell 88SS1074, SSD drives Plextor M7V.
• Silicon Motion SM2256

According to memory wear resistance tests, Samsung EVO 850 and Plextor M7V drives show very impressive results. On par with good drives with MLC memory.

And the speed is good. For example, Plextor M7V 128 GB, on an Intel SATA 3 controller, gives a read speed of 497 MB/sec, and a write speed of 247 MB/sec (measured in the proprietary Plextool program). But Plextor M7V is a budget model, one of the cheapest among all SSD drives in mid-2016.

A disk Samsung EVO 850(250 GB) gives speeds (measured in Samsung proprietary software):

• On the SATA 2 controller (Intel ICH9): 268 MB/sec read and 250 MB/sec write. This speed was also confirmed by measurements in Ubuntu Linux.
• On the SATA 3 controller (Intel): 540 MB/sec read and 505 MB/sec write.

On SATA 2, the speed is almost up to the limit of the SATA 2 standard itself. On SATA 3, the reading speed is also up to the limit of the standard. And at the same time, Samsung gives a 5-year warranty on drives of the line EVO 850. And the result is an extremely fast and very reliable disk.

Interesting inexpensive SSD drives (120 and 128 GB), as of mid-2016 (from the Yulmart assortment) in order of increasing price:

• SanDisk Z400s (5 years warranty).
• Plextor M7V
• Samsung 750 EVO Series
• SanDisk Ultra II
• Samsung 850 EVO Series
• Intel 535 AND 540 (5 years warranty).

And the record holder, in terms of speed and warranty period, is Samsung 850 PRO Series (10 years warranty). Although not cheap.

Update 2017

Many M.2 format SSD drives have appeared on sale, at prices comparable to the 2.5" SATA format. But more importantly, motherboards with an M.2 connector have appeared.

However, a clarification needs to be made. Not all M.2 format drives can provide read and write speeds significantly higher than through SATA III, that is, significantly higher than 570 MB per second. There are models that, having the M.2 format, nevertheless provide speeds at the level of only SATA III.

Speeds closer to 1 GB per second (or higher) depend on whether both the drive and motherboard support NVM Express technology.

Before purchasing, you need to check the specifications of the SSD drive and motherboard. To support NVMe on the motherboard, not only the SATA III line, but also the PCI-e lanes (2 or 4) must be connected to the M.2 connector.

Here, for example, are several motherboards with an M.2 connector and NVMe support:

• ASUS H110M-A/M.2
• ASUS H170M-PLUS
• ASUS PRIME B250M-A
• ASUS B150-PRO

And accordingly, for example, SSD drives with NVMe support:

• Plextor M8Pe, PX-128M8PeG(N)
• Samsung EVO NVMe M.2

In addition, to support NVMe you need to use a fairly recent version of the OS. Windows supports NVMe out of the box starting with version 8.1. For Windows 7, you need to install an update and this is non-trivial, because the driver needs to be integrated into the installation image. Microsoft has instructions. There is another instruction in this topic, in Russian.

On Linux you need to use kernel version 3.13 19 or higher.

What are the benefits of using an NVMe-enabled SSD drive? At a minimum, today, this is approximately twice the speed of operation compared to SATA III. And in reading mode, the speed is already 3-4 times higher than through SATA III. And over time, this gap will increase. So it makes sense to bother.

If you are buying a new computer in 2017, then I advise you to buy a motherboard and an SSD drive with NVMe support.

Update 2018

Cheap models

There are many SSDs on sale with the cheapest possible hardware platform. Manufacturers are reducing the number of processor cores, the number of memory channels, and removing the DRAM cache (the so-called DRAM-less controllers). For example, the Phison S11 controller is not only single-core, but also dual-channel and without DRAM cache. Such disks have a low price and beautiful figures for read and write speeds, in the specifications

Manufacturers of such SSD drives draw beautiful numbers in the specifications using a software trick called pseudo-SLC cache. The essence of this software solution is that part of the TLC flash memory operates in pseudo-SLC mode, that is, one bit is written to the cell instead of three. This makes it possible to significantly increase the recording speed. However, this only works as long as the write size does not exceed the size of this pseudo-SLC cache or until the disk is completely full so that there are no free cells for the pseudo-SLC cache. And then the disk produces real, sad performance. Under high recording load, such disks can be even slower than HDDs.

And of course, given the weak processor of the controller and the lack of a DRAM cache, such drives have low performance in access mode to arbitrary blocks with a queue depth of 1-4. And this is the most common operating mode for a disk in a home (non-gaming) and office computer.

Some of these models:

• WD Green and Blue
• Toshiba TR200
• Kingston A400
• Sandisk SSD Plus (SDSSDA)
• GoodRam CL100
• SmartBuy Jolt

Be that as it may, even such an SSD drive will generally be faster than an HDD.

SATA goes down in history

Of course, SSDs with the SATA interface will be produced for a long time. To replace HDD in work computers. But all major manufacturers make their best models in M.2 format and with NVMe support. The reason for this is that the SATA interface no longer allows for the data transfer speed that modern SSD drives provide. The speed limit for the SATA3 bus is approximately 570 MB per second. And modern SSD drives can transfer data at speeds of more than 1 GB per second.

So if you're looking to buy a new computer or upgrade, look for a motherboard with an M.2 connector and NVMe support. And put an M.2 NVMe SSD there. However, you need to take into account that a motherboard with an M.2 connector, or a disk in M.2 format, may not have support for the NVMe protocol - in this case, the disk will operate at SATA3 speed (SATA mode).

3D XPoint (Intel Optane memory)

The first disks (from Intel) made on a new type of memory - 3D XPoint - appeared in retail sales. This memory is fundamentally different from NAND flash memory. Firstly, it is not processed in blocks - each cell can be addressed individually. Secondly, the cells do not need to be erased before recording. Thirdly, it has a higher recording resource.

In linear read and write operations, these 3D XPoint memory drives provide speeds comparable to the fastest TLC NAND drives. But in operations of reading and writing small blocks at arbitrary addresses and with a short queue, 3D XPoint memory is faster than NAND flash. And this mode of disk operation is most common in practice.

The capacity of the first (for the retail market) 3D XPoint disks is not yet sufficient for their individual use (16 and 32 GB). And today Intel offers Optane memory technology for these drives. The 3D XPoint disk is installed in the M.2 slot and this disk is used as a cache for a regular HDD disk. It seems to me that this solution is too complicated to implement and insufficiently effective in terms of price. It's easier to use SATA or M.2 SSD. And if you use an M.2 NVMe SSD, it will also be faster than an Optane drive + HDD.

It will be interesting when Optane disks with a capacity of at least 60 GB and at a competitive (with NAND) price will appear in retail.

Good and inexpensive SSD drive models

SATA Intel SSD 545s- the minimum volume in this model line is 128 GB. The 256 GB model costs around 5,500 rubles. The drive has - DDR3 DRAM cache, 64-layer TLC 3D V-NAND Intel - Micron, 4-channel SM2259 controller, aluminum case. For the 256 GB model, read and write speeds are specified: 550 and 500 megabytes per second. These are the numbers when using a pseudo-SLC cache, its size (in the 256 GB model) is 3 GB. Past the SLC cache, the write speed is around 400 MB per second. As of summer 2018, this is the best option in the budget segment.

SATA Samsung 850MZ-7LN120BW- just 850 without the EVO suffix. There is only one model in the line so far, 120 GB. Costs around 3500 rubles. In this model, everything is mature - DRAM cache, a good controller, plus a new 64-layer TLC 3D V-NAND memory. The result is very good speed performance. A good recording resource is 75 Terabytes.

SATA Hynix SL308- the line includes models with 120, 250 and 500 GB. DRAM cache, own controller, own memory, aluminum case. Like Toshiba, Intel and Samsung, Hynix also produces SSD drives from its own components. The 120 GB model costs around 3,500 rubles.

SATA Crucial Micron 1100- the minimum volume in this model line is 256 GB. This model costs around 6,500 rubles. It uses a Marvell controller, DRAM cache and its own TLC 3D NAND memory.

M.2 NVMe Intel 760p- the minimum volume in this model line is 128 GB. The 256 GB model costs around 6,400 rubles and has a 5-year warranty. The disk has - DDR4 DRAM cache, 64-layer TLC 3D V-NAND Intel - Micron, 8-channel SM2262 controller. All together this gives fantastic read and write speeds: 3.2 and 1.3 Gigabytes per second. This is the speed of the first computers with DDR2 RAM! Of course, these are numbers when using a pseudo-SLC cache, but its size (in the 256 GB model) is approximately 6 GB, which covers requests during normal operation. Past the pseudo-SLC cache, the write speed is about 600 MB per second. According to tests, disks of this series give excellent results when performing operations with random blocks and short queues. As of summer 2018, this is the best option in the budget segment.

M.2 NVMe Samsung 960 EVO- the minimum volume in this model line is 250 GB. The 250 GB model costs around 7,000 rubles. It has the same impressive read and write speed figures: 3.2 and 1.5 Gigabytes per second. These are the numbers when using a pseudo-SLC cache, but its size changes dynamically and, if there is free space, in the 250 GB model, it can reach 13 GB. However, this disc is worse than Intel 760p, copes with reading and writing arbitrary blocks and a short queue. And this disk is option number two, if not available Intel 760p.

Pomoschnik.ru, 2016, 2017, 2018