Solid state drive ssd. Physical dimensions of both media. Types of SSD media

It probably won't be wrong to say that the computing world is entering the era of solid-state drives. Indeed, in comparison with them, hard drives are significantly inferior in power. For example, doubling your computer's RAM can increase its performance by no more than 10%. It's another matter if you equip your computer with an SSD.

Thus, a solid-state drive for a laptop purchased three years ago can increase its power by almost 3 times. This means that a laptop “upgraded” with an SSD, firstly, has performance almost equal to a modern model in the same price category. Secondly, the launch of all programs is faster, including video conversion.

Thus, the question of why a solid-state drive is needed can be answered briefly - to increase the performance of your computer or laptop. However, SSDs also have other important advantages.

Plus the first: stability. Hard drives, which have moving heads and rotating magnetic platters, are susceptible to damage and shock, unlike solid-state drives. SSD memory chips, due to the absence of moving parts in them, are not sensitive to external influences. Therefore, even after your laptop falls from a small height, all data will be saved and will not be damaged.

Plus the second: silent operation. SSDs use flash memory that responds to high-speed data transfer. In addition, thanks to flash memory, SSDs operate almost silently. True, the fan of the computer cooling system makes this plus little noticeable.

How to install a solid state drive? Most modern PCs have a bay where you can install an SSD, and thus use a solid-state drive and a hard drive in parallel. But to really improve your computer's performance, you will need to move the operating system from the hard drive to the SSD.

To simplify this procedure, there are special programs issued by manufacturing companies, as well as external containers costing from 300 rubles. Containers make it possible to use a solid-state drive as removable storage. After transferring the data to the SSD using a USB cable, the drive is removed from the external container and installed in the computer. In this case, the data is saved on the hard drive.

But what if your PC or laptop doesn't have an extra bay where you can install an SSD? In this case, you will have to replace the hard drive with it. To do this, you first need to transfer the information system to an external hard drive using an SSD with an external container, and then replace it.

How to choose a solid state drive? The main guidelines are the SSD capacity, a good combination of memory and controller, and a suitable connector. It is these factors that play a significant role in increasing computer performance after installing an SSD. Flash memory and the controller affect the data transfer speed of the solid-state drive, for example, they determine whether a movie will be copied in 45 seconds or 75.

When an SSD is connected to a laptop or PC, data is transferred through the SATA connector. It is better to choose an SSD with a SATA 3 interface; it provides higher transfer speeds; however, SATA 2, although it has half the performance, is still significantly faster than a hard drive in speed. The speed of operation is also affected by the capacity of the solid-state drive. The performance of computers equipped with a 500 GB SSD is much higher than those with a 250 GB drive or, especially, a 120 GB drive.

Of course, the capacity of an SSD directly affects its price: the larger the capacity, the more expensive the drive is. However, the ability to remain fully operational for many years will pay off the investment in the future. So, having dealt with the question of why a solid-state drive (SSD) is needed, it remains to mention the fastest models of various capacities.

To do this, we will use the results of independent testing. Computer Bild magazine compared solid-state drives in terms of data transfer speed, power consumption, heat dissipation and performance indicators. As a result, among models with a capacity of 120 GB, the Samsung SSD 840 Pro took first place, and OCZ SSDs from the Vector series showed the highest performance among SSDs with capacities of 250 and 500 GB.

What shouldn't you expect from SSDs? Firstly, low power consumption, and secondly, increased battery life. Both of these indicators remain unchanged when replacing the HDD with an SSD. Nevertheless, it is already clear that the future belongs to SSDs, and we hope our review will help you make a good choice.

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 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 write 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

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

Hard drives vs SSDs

The choice is obvious. Computer enthusiasts who have already tried SSD drives have felt the difference and do not want to go back to using a mechanical drive as a system drive. The disadvantages of SSDs - significantly higher price, small capacity - are gradually disappearing as technology develops.

The advantages of flash memory drives cannot be ignored: low access time, high data transfer rates, excellent I/O performance. We also note mechanical reliability, low energy consumption and silent operation.

At the moment, there are so many manufacturers offering SSD drives that it's not so easy to separate the wheat from the chaff. If you go straight to the test charts page, you can see how SSDs outperform HDDs. Even if you don’t look for the fastest solid-state drive, but take the performance of the most inexpensive model as a starting point, even such a drive will be many times faster than any hard drive!

Pros and cons of SSDs

It is difficult to assess the benefits of SSDs based on tests that are designed to compare different drives with each other, relative to other upgrade methods (new processor, graphics card).

As a result, average users looking to build a modern, productive PC might be advised to buy a small SSD drive and store most of their files on the hard drive, spending the bulk of their money on upgrading other PC components.

If you ask several ordinary users what kind of computer they would like to have, the answers will most likely be similar. Sandy Bridge architecture processor, at least 4 GB of RAM, good graphics card. The “default” set includes a hard drive, but SSD drives are usually out of the question. It is not right.

It would be appropriate to sacrifice a couple of hundred gigahertz of the processor clock speed by adding a system SSD drive of about 60 GB to the hard drive. This way, you can get almost all the benefits of SSD technology without going broke on purchasing a large-capacity solid-state drive.

A superficial view is not always correct

Our opinions are usually based on real, comparable data. A 2 TB drive with a spindle speed of 7200 rpm looks, without a doubt, more attractive than the old 120 GB and 5400 rpm model. If previously the throughput of the SATA interface was 300 MB/s, now it has reached 600 MB/s. As we can see, evolution is obvious, but for many such numbers mean more than real results.

In this case, we have two problems at once. First, too few users know that using a solid-state drive can actually significantly speed up applications. The second problem is the small size and high cost of SSDs.

But it’s worth repeating again: any modern SSD, regardless of model, is an order of magnitude faster than any hard drive. Let's illustrate this fact by comparing a simple SSD with one of the most powerful magnetic platter drives.

Samsung 470 Series vs. Seagate Barracuda XT

HDD: Seagate Barracuda XT, 3 TB

We chose a hi-end hard drive, which combines high performance for a HDD and large capacity. The Seagate drive is quite capable of representing the HDD as a class in this comparison. This is a modern hard drive with a capacity of 3 TB - not the maximum today, but this volume is enough for almost any PC.

Spindle rotation speed – 7200 rpm. As a latest-generation drive, the Seagate Barracuda XT combines high sequential read and write speeds, decent response time for a hard drive, and relatively high I/O performance. The drive is equipped with the latest SATA 6 Gb/s interface. However, given the real peak performance of 160 MB/s, this is clearly just a publicity stunt: it would have been enough to limit ourselves to the previous version of the SATA interface.

Seagate XT belongs to the upper price bracket (about $250). It will appeal to those users who prefer modern hardware, but are still cautiously looking towards SSDs. The drive is covered by Seagate's five-year warranty.

As an alternative, there are Hitachi Deskstar 7K2000 and 7K3000 hard drives (both 3 TB), Western Digital Black Edition 2 TB. You can find out more about modern “heavyweights” from the world of HDD in the material on our website "Four HDDs with a capacity of 3 TB" .

SSD: Samsung 470 Series, 128 GB

Representatives of this Samsung line have previously been repeatedly used by us as references in various tests, but today these drives are no longer the newest and best (see our material Samsung SSD 830 series, dedicated to the new line of Korean solid-state drives).

The 470 series is represented by disks with a capacity of 64, 128 and 256 GB, equipped with the obsolete SATA 3 Gb/s interface. If you compare the Samsung 470 series drive with the latest models from Crucial, Intel and numerous drives based on the second generation SandForce controller, it does not look so modern.

Ultimately, the Samsung 470 series SSD provides data transfer speeds of up to 260 MB/s. Some of the latest SSD models with a SATA 6 Gb/s interface are capable of exceeding 500 MB/s in serial data transfer operations. The difference is significant. Our position in this case is that even the previous generation of solid-state drives is significantly ahead of any hard drive, including the most modern models.

Samsung, Intel, and Toshiba design and manufacture SSD components in-house (the only exception is the Intel SSD 510 series, which uses a Marvell controller). All three vendors have released enough firmware to fix firmware issues, so none of them are perfect. The bottom line is that even if the Samsung 470-series drive is not exactly what computer enthusiasts dream of, this drive is quite consistent in its characteristics with a standard “mid-class” SSD, and in this sense its choice is justified taking into account the purpose of this review. If you are interested in comparing the performance of more recent SSD models, you can familiarize yourself with the results of the corresponding tests on the pages of our website.

Comparison of characteristics

Performance

As you can see in the video at the end of this article, an SSD drive can significantly speed up a modern computer - whether we are talking about the speed of launching applications, loading levels in games, or importing large amounts of data. Why is this happening?

First of all, the success of SSDs is associated with significantly higher data transfer rates. 2.5" hard drives reach 60-100 MB/s, 3.5" - 100-150 MB/s. Moreover, these indicators reflect the performance of HDDs in the most favorable conditions for them. The characteristics that vendors like to cite in specifications for this or that HDD model relate to sequential data read/write operations - here the lag of hard drives is least apparent. When the hard disk head moves to another disk partition/sector, the speed of operations decreases rapidly.

Disk usage modes in which I/O performance comes to the fore are not favorable for HDDs. An example is loading Windows, which involves reading a huge number of small blocks of data. Here, when comparing a hard drive with an SSD, the picture is even sadder.

The data transfer speed in such modes drops to several MB/s. This applies to even the newest and most productive HDD models. Thus, hard drives do a good job of sequentially copying large files, but their use as a system drive is not optimal.

SSD uses flash memory to store data. Such drives consist of many memory cells that are used in parallel to each other and interact with the controller through several data channels. Such an architecture is capable of providing sequential read speeds from a couple of hundred MB/s to record values of more than 550 MB/s. However, as we have already noted, hard drives also perform well in serial data transfer.

The critical mode for SSDs is data writing operations, since only data blocks of a certain size can be written. If you need to write only a few bits to the disk, a whole series of operations will be required - reading, erasing and finally rewriting one or two blocks.

Thus, it is not uncommon for hundreds of MB/s to turn into just a few dozen in practice. But while we are talking about blocks of about 4 KB in size, which are used by modern file systems, SSDs are still 10-20 times faster than HDDs, providing performance in the tens of MB / s, while in the case of hard drives it drops to KB /s due to delays in head positioning. In real work, such a difference is not just noticeable, but striking.

Energy consumption and heating

SSDs consume, at most, a few watts. Hard drives can use 10 watts per hour or more if they are actively copying files. Modern SSDs do not heat up at all. Hard drives, on the other hand, often require cooling. Normal air circulation inside your computer case will most likely be enough, but the issue of proper cooling of the disk system is still worth considering when assembling a PC yourself.

Design features and reliability

SSDs have no moving parts, which makes them very reliable. Theoretically, it's possible that you expose the solid-state drive to extremely high vibration or shock, so that the solder joints of the chips fail. In practice, this situation is unlikely.

Exactly the same tiny chance of breaking a solder exists with hard drives, but the real danger lies in the presence of moving elements - magnetic plates that rotate at high speed, and read/write heads. The operating principle of a modern HDD is reminiscent of an old-fashioned gramophone.

Mechanical parts have a certain resource and, in general, the reliability of the hard drive is lower. Any strong shock can turn a working hard drive into a piece of useless hardware. Modern HDDs have a certain “margin of safety” in relation to shock loads (which is especially true for 2.5” drives for laptops), but from the point of view of mechanical reliability they are still significantly inferior to SSDs.

Whether an SSD drive will survive a hard drive is impossible to say with certainty. It is known that HDDs are more prone to breakdowns, since their design combines electronics and mechanical elements. On the other hand, SSDs are more sensitive to firmware and we know of cases where, due to a firmware failure, a solid-state drive became unusable. The potential reliability issues for SSDs and HDDs are different, but exist in both cases. You can learn more about the issue of comparing the reliability of SSDs and magnetic platter drives in the article "Which is more reliable: SSD or HDD?" .

Test bench configuration

Performance Test Bench
CPU	Intel Core i7-2500K (Sandy Bridge): LGA 1155, 32 nm process technology, D2 stepping, 4 cores/4 threads, 3.3 GHz, 6 MB shared L3 cache, HD Graphics 3000, TDP 95 W, Turbo Boost max. frequency 3.7 GHz
Motherboard (LGA 1155)	Gigabyte Z68X-UD3H-B3, rev. 0.2, Intel Z68 Express chipset, BIOS version F3
RAM	2 x 2 GB DDR3-1333, Corsair TR3X6G1600C8D
System SSD	Intel X25-M G1, 80 GB, firmware 0701, SATA 3 Gb/s
SATA controller	Intel PCH Z68 SATA 6 Gb/s
power unit
Benchmarks
Performance Measurements	h2benchw 3.16 PCMark 7 1.0.4
	Iometer 2006.07.27 File server Benchmark Web server Benchmark Database Benchmark Workstation Benchmark Streaming Reads Streaming Writes 4K Random Reads 4K Random Writes
System software and drivers
operating system	Windows 7 x64 Ultimate SP1
Intel Inf Driver	9.2.0.1030
Intel Rapid Storage Driver	10.5.0.1026

Test bench for measuring the energy consumption of an SSD drive
CPU	Intel Core 2 Extreme X7800 (Merom), 65 nm, E1 stepping, 2 cores/2 threads, 2.6 GHz, 4 MB L2 cache, 44 W TDP
Motherboard (Socket 478)	MSI Fuzzy GM965, revision 1.0, Intel GM965 chipset, BIOS version A9803IMS.220
RAM	2 x 1 GB DDR2-666, Crucial BallistiX CM128M6416U27AD2F-3VX
System HDD	Western Digital WD3200BEVT, 320 GB, SATA 3 Gbit/s, 5400 rpm
SATA controller	Intel ICH8-ME
power unit	Seasonic X-760 760 W, SS-760KM Active PFC F3
Benchmarks
Playing video	VLC 1.1.1 Big_Buck_Bunny_1080p
I/O Performance	Iometer 2006.07.27 Database Benchmark Streaming Writes
System software and drivers
operating system	Windows 7 x64 Ultimate SP1
Intel Inf Driver	9.2.0.1021
Intel Rapid Storage Driver	15.12.75.4.64

Test bench to evaluate performance in real applications
CPU	Intel Core i3-530 (Clarkdale) 32 nm, C2 stepping, 2 cores / 4 threads, 2.93 GHz, L2 cache 256 KB, L3 cache 4 MB, HD Graphics, TDP 73 W
Motherboard (LGA 1155)	MSI H57M-ED65, revision 1.0, Intel H57 chipset, BIOS version 1.5
RAM	2 x 4 GB DDR3-1333, Kingston KHX1600C9D3K2/8GX
Controller	Intel PCH H57 SATA 3 Gb/s
power unit	Seasonic X-760 760 W, SS-760KM Active PFC F3
Test software
Performance Measurements	SYSmark 2012
Operating system and drivers
operating system	Windows 7 x64 Ultimate SP1 (updated on 2011-08-10)
Intel Inf Driver	9.2.0.1030
Intel Rapid Storage Driver	10.6.0.1002

The results of these tests are indicative of most SSD and hard drive models. The tested components were selected to obtain the best comparison for both configuration options. The drives are tested on very similar systems. The purpose of this review is to evaluate the benefits of using an SSD as a system drive. We are not trying to prove that SSDs have advantages in all aspects (in fact, we do not recommend using them for data storage).

Test results

Sequential Read/Write

CrystalDiskMark and Iometer clearly show significantly higher data transfer speeds compared to a high-end hard drive. If you regularly read reviews, this fact is unlikely to be news to you.

Random Read/Write

The following results are very indicative from the point of view of booting the Windows operating system. When it comes to the real difference in everyday use, the SSD's separation from the hard drive may not be that significant, but in the synthetic test the difference is striking.

According to CrystalDiskMark, the hard drive works with 4 KB blocks in random read mode at a speed of 1.6 MB/s, write speed - 0.7 MB/s. Similar indicators for SSDs are an order of magnitude higher: 19.7 MB/s for write operations, 70.6 MB/s for read operations.

As the queue depth increases, SSD performance increases even further, which is explained by the fuller use of its multi-channel architecture: 129.4 MB/s for write operations and 70.5 for read operations. For HDDs, we also see a threefold increase in random write speed (up to 2.1 MB/s) thanks to NCQ support. However, the lag behind the SSD increases even further.

For larger block sizes (512 KB in this test), the hard drive can provide much better speeds than we just saw. However, SSD retains its leadership here too. A modern solid-state drive with a 6 Gb/s interface would provide a more serious lead over the HDD.

The balance of power is obvious: in the random search test using 4 KB blocks, the HDD provided a result of about 700 KB/s, the SSD - 18.4 MB/s.

At a large queue depth (64 commands), the SSD outperforms the hard drive in the random search test by 40-50 times.

In the Iometer read performance test, the Samsung 470 128GB achieves 28,000 IOPS performance. The hard drive shows a result of 102 operations per second.

When writing, an SSD operates on blocks of data: writing even just a few bytes requires a full cycle of rewriting the entire block. Therefore, in write operations, the SSD separation is not so glaring, but we are still talking about a difference of an order of magnitude. Iometer shows a result of 1343.5 I/O operations for SSD and 132.5 for HDD.

I/O performance and access time

The Database boot script paints a clear picture: SSD is 12 times faster than HDD.

In the Web Server scenario, the SSD's superiority is even more significant, since read operations account for the bulk of the workload in this test.

In the workstation performance test, the balance of power does not change.

Access time

Unlike a hard drive, access time on an SSD is hardly measurable.

PCMark 7

Futuremark PCMark 7 simulates a typical PC experience. With rare exceptions, an SSD is 2-4 times faster than a hard drive. Note that in these tests the overall system performance changes, taking into account the influence of the CPU and video card. Thus, here we see a picture close to that which occurs during everyday use of a PC.

Exceptions include video processing in Windows Movie Maker, as well as the Windows Media Center boot script. In these tests, the SSD and HDD provide similar results.

Energy consumption

The smallest difference between an SSD and a hard drive in terms of energy consumption is observed in the streaming write stress test. But even in this test, one hard drive consumes about the same amount of power as three SSDs.

Energy efficiency: performance per watt

In database applications, the Samsung 470 outperforms the Seagate hard drive by 476 times (based on IOPS per watt).

In the streaming recording efficiency test, the solid-state drive outperformed the hard drive by 7 times.

Here it is necessary to briefly highlight the issue of measuring “capacity per watt”, since in this indicator SSDs are inferior to hard drives. To provide the amount of disk space corresponding to the Seagate Barracuda XT 3 TB, you will need to assemble an array of one and a half dozen SSDs. In this context, discussing “capacity per watt” can only be discussed in theory. If you need a lot of storage space, HDDs currently have no alternative.

SYSmark 2012

The benchmark developed by BARCo is not often used in tests. The fact is that some companies, including AMD and nVidia, do not trust this test package, which is explained by the specific composition of the package: it focuses on boot scenarios that have little to do with everyday PC use. A significant percentage of the overall performance ranking is allocated to OCR or archiving operations. It is worth noting that AMD indicates the presence of certain optimizations for Intel architecture in SYSMark.

Please note that in SYSMark tests the SSD is very slightly ahead of the HDD. We can say that the results are the same. The reason is that in this case it is not possible to isolate the impact of other computer subsystems on the final result.

Windows boot speed

A computer with a system SSD drive also turns off faster - in five seconds instead of eight in the case of an HDD.

Launching applications

We use a script that opens four applications at the same time. As is the case with loading the OS, the speed advantage for launching applications on a system with an SSD drive is quite significant. You can see how this looks in practice in the video.

Running applications on SSD and hard drive

So, we used a script that opens several applications at the same time and captures the difference in the form of a short video. The script runs immediately after Windows boots, after which it waits 30 seconds for all processes to complete. The script launches Internet Explorer 9 (offline version of the THG site), Microsoft Outlook (the same set of user folders as in SYSmark 2012), a “heavy” PowerPoint presentation and a large image in Adobe Photoshop.

We missed this test four times in a row. File caching slightly reduces the loading time for the fourth “run”, but this can only be noticed in relation to the HDD. Let's watch the video:

Run multiple applications on HDD and SSD

Our test simulates a work scenario when you turn on your computer and open several applications at once - for example, an office program, a web browser, a messenger, an image editor. As long as the system has a sufficient amount of RAM (that is, at least 4 GB at the moment), CPU performance is in second place after the disk subsystem. In other words, plus or minus 500 MHz of the processor frequency is not so significant, but replacing a hard drive with an SSD, on the contrary, significantly affects the result.

Here the question arises - is the choice of a specific SSD model important? In our opinion, this issue is not so fundamental. Even if you opt for the latest drive with the SandForce SF-2200 controller, which exceeds the 500 MB/s mark for sequential reading, the difference compared to the not-so-new SSD model we used in this test will not be too noticeable. If you try to use an SSD as a system drive for the first time, then you definitely won’t want to go back to hard drives.

Any modern SSD improves system responsiveness

For those computer enthusiasts who have not yet tried using an SSD, we can safely recommend this upgrade option. Undoubtedly, the game is worth the candle. While not every benchmark reflects the benefits of using an SSD as system storage (in particular, we don't see a significant gap in SYSMark), the real difference in performance is noticeable.

We compared one of the largest, fastest and most expensive hard drives on the market - the Seagate Barracuda XT - with a modest, not the latest Samsung 470 solid state drive. Of course, you can opt for a more “advanced” model, but even if you choose With respect to a budget model, you can get all the benefits of an SSD.

At the same time, we are not at all trying to retire hard drives. When it comes to storing files, there is no alternative to this type of drive. An SSD should be used to install an operating system and place executable program files and application caches on it.

For most cases, the ideal configuration of a modern PC includes a system SSD drive and a large hard drive on which movies, music, images, and documents are stored. Systems without an SSD are considered budget configuration options, and computers with only a solid-state drive are almost never found in nature.

Solid state drives (SSDs) have been on the market for a long time, but they have been gaining more and more popularity recently. SSD drives are quite expensive, but they greatly improve system performance due to their very high speed of reading and writing data.

Unlike conventional hard drives, instead of magnetic tracks, a new technology is used - flash memory. But in addition to the great advantage in performance, there are several other disadvantages here - service lines, small volume and high price. In this article we will try to figure out how to choose an SSD drive for a computer, and also look at what they are and how they differ from each other. But first you need to find out what SSD drives are.

SSD or Solid State Drive is a storage device without moving elements based on memory chips or in other words, a solid state drive.

A typical hard drive consists of a magnetic disk rotating at high speed and a head for reading and writing data. Data storage is performed by magnetizing and demagnetizing the desired cells. But working with the cell, changing the disk rotation speed, and most importantly, moving the recording head takes too much time. Therefore, the hard drive cannot be very fast.

But an SSD drive solves this problem. Here, instead of this whole complex mechanism, flash memory is used. Thanks to this, there is no longer any need to move the recording head; recording to any point on the disk is instantaneous.

But chip-based memory technology is more expensive than conventional hard drives. In addition, flash memory has one very undesirable property - a limited number of rewrites. Therefore, manufacturers have to come up with different ways of cell placement and compensation to ensure that their drives last as long as possible.

So that you can choose the right ssd drive for your computer, you first need to consider what types of drives exist.

Types of SSD drives

During the development of this technology, several types of SSD drives have appeared; they differ in size, method of connection to the computer, operating speed and method of placing memory cells.

Dimensions and connection methods

The size, method of connecting the SSD drive to the motherboard and operating speed are related to each other, because these characteristics depend specifically on the connection interface. Let's look at the most common ways to connect an SSD so that you know which ssd to choose:

SATA- these SSD drives connect to the same interface as regular HDD drives. To be compatible with the installation space, these drives have a housing measuring 9x7x2.5 centimeters, which corresponds to the size of the HDD. Nowadays, they are used most often because they can be easily installed in any computer or laptop instead of a regular hard drive. But this option has a limitation - the maximum data transfer speed is 6 GB/second. For an HDD this is a very large figure, but some SSDs can develop even more.
mSATA- exactly the same connection interface as SATA, and therefore the same operating speed. Only there is not such a large building here. This type of SSD is often used for laptops. The only difference between this type of disk is the size.
PCIe- these drives look like a regular PCI card and, thanks to the use of this interface, can achieve data transfer speeds of up to 30 Gb/sec. But they can only be used in personal computers due to their size, and also cost two or even three times more than regular SATA SSDs.
NVMe- a modification of PCIe SSD drives that provides even greater performance thanks to special optimizations, but at the moment it is only compatible with new motherboards. The case looks exactly the same as the PCIe one.
M.2. is a smaller version of an SSD drive for PCI. It works using the same protocol and allows you to develop the same speed of data processing, but instead of a large case it is made in the form of one small board. Most modern boards already support slots of this type, but they can also be connected simply via PCI.

Methods for organizing memory cells

Based on the way SSD memory cells are organized, drives are divided into different numbers of bits that are stored in one cell. In fact, the less, the greater the rewrite resource and the speed of operation, but at the same time the higher the price. Therefore, manufacturers are trying to reduce the cost of production by increasing the amount of data in one cell. Currently there are the following types of memory:

SLC NAND- This type of memory was developed quite a long time ago. One cell contains one bit of data. It guarantees maximum performance and up to ten thousand data overwrites, but is very expensive and therefore not released.
MLC NAND is the next generation of flash memory, in which there are two bits per cell. The number of possible rewrites is reduced to three thousand times, and the operating speed is halved. But the price of such devices is already more or less acceptable.
TLC NAND- in this standard, one cell already contains 3 bits of data and the rewriting resource drops to 1000. But they are even cheaper. Manufacturers have found a way out of the situation by adding various balancing controllers, which replace the failed cells with reserve ones, and also try to give the same load to all cells. A cache from SLC memory is also used. All this allows us to guarantee the operation of the SSD for up to 3 years or more.

Nowadays TLC and MLC with various optimizations are most often used.

How to choose an SSD drive?

Now that you already know what SSD drives are, let's look at how to choose an SSD drive for your computer. New users only pay attention to volume, price and size. But you also need to take into account the type of memory placement, connection method and controller manufacturer.

SSD memory capacity

The larger the size, the higher the price of the device, but at the same time, the greater the rewriting resource, because the controller has more space to redistribute the load between all cells. Most often, SSD drives come in sizes of 128, 256 GB and 1 TB. Most often, users take a 128 GB SSD for the system.

Connection method

In fact, there are only two connection methods: using the SATA interface and PCI. SATA is more common and versatile. This SSD drive can be installed in both a computer and a laptop. But if you want very high speed, it is better to choose the PCI interface.

Memory type

To find out which ssd is better to choose 2016 for your computer, you need to pay attention to the type of memory. The first type of memory, SLC, is no longer available. There are two types common in the market - MLC and TLC. The first is more expensive, but has a recording resource of 3,000 thousand times, and the speed of working with data is 50 milliseconds. Such disks can last 5-7 years with normal use, but are more expensive.

Discs using TLC memory have a write life of 1000 times, a 75 millisecond read time and a service life of about three to five years. For a home computer, it is quite possible to choose TLC memory. But if you copy large files very often, then it is better to choose MLC.

Chip manufacturer

There is one more very important parameter that is worth paying attention to. This is the manufacturer of the controller chip. On the one hand, it may seem that this does not matter, but each manufacturer has its own characteristics and disadvantages.

SandForce- This is one of the most popular controllers. It is quite cheap and has good performance. The main feature is the use of compression when writing data to the media. But there is a drawback - when the disk is full, the recording speed drops significantly;
Marvel- similar to SandForce, has excellent operating speed, but it no longer depends on the disk full percentage. Disadvantage - too expensive;
Samsung- also quite popular controllers. They have support for AES encryption at the hardware level, but sometimes you can observe a decrease in speed due to problems with the garbage collection algorithm;
Fizon- has excellent performance, a low price and the absence of any problems that would reduce speed. But there is a drawback here. It performed poorly in random write and read operations;
Intel- better than Fizon, but much more expensive.

The main manufacturers of memory boards are Samsung, SanDisk, Intel and Toshiba. But memory boards are not that different, so the choice of board manufacturer does not matter much.

First SSD, or solid state drives using flash memory, appeared in 1995, and were used exclusively in the military and aerospace fields. The huge cost at that time was compensated by unique characteristics that allowed the operation of such disks in aggressive environments over a wide temperature range.

In the mass market, drives SSD appeared not so long ago, but quickly became popular, as they are a modern alternative to a standard hard drive ( HDD ). Let's figure out what parameters you need to choose a solid-state drive by, and what it actually is.

Device

Out of habit, SSD is called a “disk”, but it can rather be called “ solid parallelepiped", since there are no moving parts in it, and nothing shaped like a disk either. The memory in it is based on the physical properties of the conductivity of semiconductors, so SSD– a semiconductor (or solid-state) device, while a regular hard drive can be called an electro-mechanical device.

Abbreviation SSD just means “ solid-state drive ", that is, literally, " solid state drive" It consists of a controller and memory chips.

Controller– the most important part of the device that connects the memory to the computer. Main characteristics SSD– data exchange speed, power consumption, etc. depend on it. The controller has its own microprocessor that works according to a preinstalled program and can perform the functions of correcting code errors, preventing wear, and cleaning debris.

Memory in drives can be either non-volatile ( NAND), and volatile ( RAM).

NAND memory initially won against HDD only in the speed of access to arbitrary memory blocks, and only since 2012 the read/write speed has also increased many times over. Now in the mass market drives SSD are presented by models with non-volatile NAND-memory.

RAM The memory features ultra-fast read and write speeds, and is built on the principles of computer RAM. Such memory is volatile - if there is no power, the data is lost. Typically used in specific areas, such as speeding up work with databases, it is difficult to find on sale.

Differences between SSD and HDD

SSD differs from HDD First of all, the physical device. Thanks to this, it boasts some advantages, but also has a number of serious disadvantages.

Main advantages:

· Performance. Even from the technical characteristics it is clear that the read/write speed is SSD several times higher, but in practice the performance can vary by 50-100 times.
· No moving parts, and therefore no noise. This also means high resistance to mechanical stress.
· Random memory access speed is much higher. As a result, the speed of operation does not depend on the location of files and their fragmentation.
· Much less vulnerable to electromagnetic fields.
· Small dimensions and weight, low power consumption.

Flaws:

· Resource limitation for rewrite cycles. This means that a single cell can be overwritten a certain number of times - on average, this figure varies from 1,000 to 100,000 times.
· The cost of a gigabyte of volume is still quite high, and exceeds the cost of a regular HDD several times. However, this drawback will disappear over time.
· Difficulty or even impossibility of recovering deleted or lost data due to the hardware command used by the drive TRIM, and with high sensitivity to changes in supply voltage: if memory chips are damaged in this way, information from them is lost forever.

In general, SSDs have a number of advantages that standard hard drives do not have - in cases where performance, access speed, size and resistance to mechanical stress play a major role, SDD persistently displaces HDD.

How much SSD capacity will you need?

The first thing you should pay attention to when choosing SSD– its volume. There are models on sale with capacities from 32 to 2000 GB.

The decision depends on the use case - you can install only the operating system on the drive, and be limited by the capacity SSD 60-128 GB, which will be quite enough for Windows and installation of basic programs.

The second option is to use SSD as the main media library, but then you will need a disk with a capacity of 500-1000 GB, which will be quite expensive. This only makes sense if you work with a large number of files that need to be accessed really quickly. In relation to the average user, this is not a very rational price/speed ratio.

But there is one more property of solid-state drives - depending on the volume, the write speed can vary greatly. The larger the disk capacity, the faster the recording speed, as a rule. This is due to the fact that SSD capable of using several memory crystals in parallel at once, and the number of crystals grows along with the volume. That is, in the same models SSD with different capacities of 128 and 480 GB, the difference in speed can vary by about 3 times.

Considering this feature, we can say that now the most optimal choice in terms of price/speed can be called 120-240 GB SSD models, they will be enough to install the system and the most important software, and maybe even for several games.

Interface and form factor

2.5" SSD

The most common form factor SSD is a 2.5 inch format. It is a “bar” with dimensions of approximately 100x70x7mm; they may vary slightly among different manufacturers (±1mm). The interface of 2.5” drives is usually SATA3(6 Gbps).

Advantages of the 2.5" format:

Prevalence on the market, any volume available
Convenient and easy to use, compatible with any motherboard
Reasonable price

Disadvantages of the format:

Relatively low speed among ssds - up to a maximum of 600 MB/s per channel, versus, for example, 1 Gb/s for the PCIe interface
AHCI controllers that were designed for classic hard drives

If you need a drive that is convenient and easy to mount in a PC case, and your motherboard only has connectors SATA2 or SATA3, That 2.5" SSD drive- This is your choice. The system and office programs will obviously load faster compared to the HDD, and the average user will not notice much of a difference with faster solutions.

mSATA SSD

There is a more compact form factor - mSATA, sizes 30x51x4 mm. It makes sense to use it in laptops and any other compact devices where installing a regular 2.5” drive is impractical. If they have a connector, of course. mSATA. In terms of speed, this is still the same specification SATA3(6 Gbps), and is no different from 2.5".

M.2 SSD

There is another, most compact form factor M.2, gradually replacing mSATA. Designed mainly for laptops. Dimensions - 3.5x22x42(60.80) mm. There are three different lengths of bars - 42, 60 and 80 mm, please pay attention to compatibility when installing in your system. Modern motherboards offer at least one U.2 slot for the M.2 format.

M.2 can be either with a SATA or PCIe interface. The difference between these interface options is in speed, and quite large at that - SATA drives boast an average speed of 550 MB/s, while PCIe, depending on the generation, can offer 500 MB/s per lane for PCI-E 2.0. and speeds up to 985 Mb/s per PCI-E 3.0 line. Thus, an SSD installed in a PCIe x4 slot (with four lanes) can exchange data at speeds of up to 2 Gb/s in the case of PCI Express 2.0 and up to almost 4 Gb/s when using PCI Express third generation.

The differences in price are significant; an M.2 form factor drive with a PCIe interface will cost on average twice as much as a SATA interface with the same capacity.

The form factor has a U.2 connector, which may have connectors that differ from each other keys– special “cutouts” in them. There are clues B and and also B&M. Differ in bus speed PCIe: key M will provide speed up to PCIe x4, key M speed up to PCIe x2, like a combined key B&M.

B- the connector is incompatible with M- connector, M-connector, respectively, with B- connector, and B&M The connector is compatible with any. Be careful when purchasing format M.2, since the motherboard, laptop or tablet must have a suitable connector.

PCI-E SSD

Finally, the last existing form factor is as an expansion board PCI-E. Mounted in the slot accordingly PCI-E, have the highest speed, order 2000 MB/s read and 1000 MB/s write. Such speeds will cost you a lot: obviously, you should choose such a drive for professional tasks.

NVM Express

There are also SSD having a new logical interface NVM Express, designed specifically for SSDs. It differs from the old AHCI in even lower access latencies and high parallelism of memory chips due to a new set of hardware algorithms.
There are models on the market with a connector M.2, and in PCIe. The only downside of PCIe here is that it will take up an important slot, which may be useful for another board.

Since the standard NVMe designed specifically for flash memory, it takes into account its features, while AHCI still just a compromise. That's why, NVMe is the future of SSDs, and will only get better and better over time.

What type of SSD memory is better?

Let's understand memory types SSD. This is one of the main characteristics SSD, determining the cell rewriting resource and speed.

MLC (Multi-Level Cell)- the most popular type of memory. Cells contain 2 bits, as opposed to 1 bit in the old type SLC , which is almost no longer on sale. Thanks to this, there is a larger volume, which means lower cost. Recording resource from 2000 to 5000 rewrite cycles. In this case, “overwriting” means overwriting each cell of the disk. Therefore, for a 240 GB model, for example, you can record at least 480 TB of information. So, such a resource SSD even with constant intensive use, about 5-10 years should be enough (during which time it will still become very outdated). And for home use, it will last for 20 years, so the limited rewrite cycles can be ignored altogether. MLC– this is the best combination of reliability/price.

TLC (Triple-Level Cell)- from the name it follows that here 3 bits of data are stored in one cell at once. Recording density here compared to MLC higher by whole 50% , which means the rewriting resource is less - only 1000 cycles. The access speed is also lower due to the higher density. The cost now is not much different from MLC. It has been widely used in flash drives for a long time. The service life is also sufficient for a home solution, but the susceptibility to uncorrectable errors and “dying out” of memory cells is noticeably higher, and during the entire service life.

3D NAND- This is rather a form of memory organization, and not its new type. There is both MLC, so TLC 3D NAND. Such memory has vertically arranged memory cells, and an individual memory crystal in it has several levels of cells. It turns out that the cell has a third spatial coordinate, hence the prefix "3D" in the memory name - 3D NAND. It is distinguished by a very low number of errors and high endurance due to a larger technical process of 30-40 nM.
The manufacturer's warranty for some models reaches 10 years of use, but the cost is high. The most reliable type of memory available.

Differences between cheap SSDs and expensive ones

Disks of the same capacity, even from the same manufacturer, can vary greatly in price. A cheap SSD may differ from an expensive one in the following ways:

· Cheaper type of memory. In ascending order of cost/reliability, roughly: TLC≥ MLC ≥ 3D NAND.
· Cheaper controller. Also affects read/write speed.
· Clipboard. The cheapest SSD may not have a clipboard at all, this does not make them much cheaper, but it noticeably reduces performance.
· Protection systems. For example, expensive models have protection against power interruption in the form of backup capacitors, which allow the write operation to be completed correctly and not lose data.
· Brand. Of course, a more popular brand will be more expensive, which does not always mean technical superiority.

Conclusion. What is more profitable to buy?

It is safe to say that modern SSD The drives are quite reliable. The fear of data loss and the negative attitude towards solid-state drives as a class are completely unjustified at the moment. If we talk about more or less popular brands, then even cheap TLC The memory is suitable for budget home use, and its resource will last you for at least several years. Many manufacturers also provide a 3-year warranty.

So, if you are limited in funds, then your choice is a capacity of 60-128 GB to install the system and frequently used applications. The type of memory is not so critical for home use - TLC will it be or MLC, the disk will become obsolete before the resource is exhausted. All other things being equal, of course, it is worth choosing MLC.

If you are ready to look into the mid-price segment and value reliability, then it is better to consider SSD MLC 200-500 GB. For older models you will have to pay about 12 thousand rubles. At the same time, the volume is enough for you for almost everything that needs to work quickly on your home PC. You can also take models of even higher reliability with memory crystals 3D NAND .

If your fear of flash memory wearing out reaches panic levels, then it's worth looking at new (and expensive) technology in the form of storage formats 3D NAND. All jokes aside, this is the future. SSD– high speed and high reliability are combined here. Such a drive is suitable even for important server databases, since the recording resource here reaches petabyte, and the number of errors is minimal.

I would like to include drives with an interface into a separate group PCI-E. It has high read and write speed ( 1000-2000 Mb/s), and on average more expensive than other categories. If you prioritize performance, then this is the best choice. The disadvantage is that it takes up a universal PCIe slot; motherboards of compact formats may only have one PCIe slot.

Beyond competition - SSD with NVMe logical interface, the reading speed of which exceeds 2000 MB/s. Compared to compromise logic for SSD AHCI, has much greater queue depth and concurrency. High price in the market, and the best characteristics - the choice of enthusiasts or professionals.