Which ssd is suitable for a laptop. Blackout protection. How does an SSD work?
Now it seems that SSDs have always been around. Like, where would we be without them? In fact, although the first models appeared in the early nineties, SSDs have become more or less widespread since 2009. At first they were a flash drive with a SATA interface, but gradually grew wiser and gained mass useful functions, making it possible to hide the inferiority of flash memory compared to magnetic plates in normal hard disks (yes, that’s right!). Let me emphasize that in this text we are talking exclusively about 2.5-inch consumer SSDs with SATA interface. I don’t see any point in writing about corporate models with PCI-Express, but it’s better to talk about models with M.2 for ultrabooks and advanced motherboards separately.
I often hear that I want to switch to an SSD, but I know that they are not reliable, there are so many write cycles and that’s it. That's why I don't move on. Of course, correct solution. In the metro, trains sometimes stop abruptly. You can fall and get a bump. Therefore, there is no need to take the subway. Cars crash. We cross it out. And in childhood, a bicycle is generally a shaitan machine. If a child wants to ride, let him do it in the elevator. With grandma. And take some water with you.
If you judge by only one indicator, the number of write cycles, then an SSD is a quiet horror. On a regular hard drive, you can write until you’re crazy about carrots, but here it’s like three thousand times – and that’s it, dammit. An inquisitive guy can finish it in a couple of days. Horror, horror, we won’t take it.
I’ll tell you something completely terrible now. Three thousand is ideal. In practice, flash memory can “wear out” after just a couple of thousand cycles. And this is the case if there is MLC type memory inside the SSD. And the newfangled TLC even has an official threshold of 1000 cycles. And the kirdyk-babai can sneak up after 700-800. There are, however, SLC-type memory, where the number of write cycles reaches 100,000, but it costs about 10 bucks per gigabyte. You can estimate how much even the affordable 128 GB will cost.
But here's the thing. I have an Intel SSD. He works for me at different computers since 2009. First, the home system has three years as the main one. Then on NAS around the clock until the end of 2014. And so far, according to all tests, the flash memory in it is like new. The controller, however, is one of the first ones, and cannot really do anything, so the recording speed dropped to a ridiculous 26 MB/s. But if you format it, it will again be more than a hundred. And reading remains at the level of 250 MB/s, which is quite acceptable even in today’s times.
How is this possible? That's how. The Politburo, you know, isn’t full of fools. AND SSD controller will never allow data to be written a thousand times in a row to the same cell. He will carefully select the newest ones and write in them first. So that everyone ages evenly. If the drive is not full and there is enough free space(say, 60 gigabytes), it is unlikely that you will be able to use the SSD until it wears out in the foreseeable future. There is one more trick. Many consumer SSDs have a stated capacity of 120, 240 or 480 GB. So, in fact, there is 128, 256 or 512 GB of memory, just the hidden volume is used as a safety net. And if you wipe the flash within the stated volume, it will be replaced with a spare one. And you won't notice anything for a long time.
Therefore, in practice, even an SSD with unreliable TLC flash memory will live longer than the time when you want to change it due to insufficient capacity. Unless, of course, it dies due to a defect, an electrical surge, a swollen capacitor, or a controller failure. But regular HDDs are not immune to this.
There is, perhaps, only one way to reliably remove an SSD within short term. A videographer friend of mine mastered it. Several times a day, he recorded a hundred or two gigabytes of data from the camera to the SSD. I sent them on air, erased them, and recorded them again the next day. The SSD was clogged almost all the way. In this mode, the first two SSDs died within six months. Before buying the third one, he asked me what was going on, should I go back to the HDD. I explained to him some principles SSD operation and advised from now on to take not exactly custom SSDs, for which the recommended recording volume is 20 GB per day, but something Enterprise class with a limit of 80-100 GB. Plus I advised taking the volume not 256 GB, but 480. And leaving some free space. Similar to how part of agricultural land is annually left fallow, without being used for its intended purpose. Apparently, the advice came in handy. I haven’t heard any mournful lamentations for a year and a half now.
Probably, a similar effect can be achieved if you download huge volumes of torrents every day, erase them, and download them again. I don't know, I haven't tried it. In my humble opinion, SSD is designed for recording operating system, the most important applications (for example, a graphics or video editor), as well as games. Yes, yes, games. They load such inhuman amounts of data into memory that it is better to do this with an SSD. For everything else, there are traditional HDDs located nearby. If an SSD is installed in a laptop, and there is simply no space for an HDD, I recommend getting an external one. At current speed USB difference with an internal location will be insignificant. And, in any case, it is extremely useful to organize automatic backup of the SSD to the HDD. Once a week will be enough.
SSD, unlike HDD, is not bothered by kicks to the case in case of an unsuccessful battle in World of Tanks; it is quite indifferent to the temperature around it. A laptop with an SSD will not lose data even after being dropped in a working state, which personally always worries me more broken screen. And you can twist and turn it as you like. Well, it’s also definitely FASTER. And not so much in absolute terms (although that too), but in terms of data access time. So, if you approach the matter with understanding, SSDs are very useful. The main thing is not to destroy it deliberately, like the men in the joke about the Japanese chainsaw.
Yes, the SSD does not wear out from reading data. Only from recording. For some reason many people don’t know this.
And now we come to the most important thing - how to choose an SSD to make you happy? Boring hardware guys will start telling you all sorts of things about controllers, sequential recording, a bunch of benchmarks and the like. But I respect your time and will explain everything simply and quickly.
1) Decide on the volume. Even if there is a lot of money, and it has already burned a hole in your pocket more than once, you don’t need to take something crazy like a terabyte. SSDs are poorly designed for storing and processing large amounts of data. If you need a file dump, take an HDD, it will be much cheaper and more reliable. For a normal person, a volume of 240-256 GB is quite sufficient. If you need to carry large video files and a database of photos with you (with the reservations made above), you can take 480-512. You can do more, but I don’t beat people’s hands and I don’t count other people’s income. But a terabyte will most likely be based on TLC, which - here's the paradox - is designed very poorly for recording large amounts of data. But I would advise using 128 GB models with caution, because their write speed is often half that of 256 GB models. And what is 128 GB in these days? Laughter alone. “Tanks” are already reaching thirty.
2) Don't worry about the controller. No, I'm serious. Boring guys write whole stories about them, but you have to understand that even not the most successful of them modern models provide more than 400 MB/s when reading and 200 MB/s when writing. Well, if you're really unlucky - 150 MB/s. But, most likely, you will be lucky. Is there a difference between reading 400 MB/s and, say, 500 MB/s? In the benchmarks there is, in real life No. It's even more interesting with a recording. Is there some source from which you will write in a stream? large files with a speed of at least 150 MB/s? I couldn’t imagine something like this. All real situations are much slower. Plus, the SSD has a buffer with a capacity of 128-512 MB, where all relatively small files are dumped, and this happens instantly. So, whatever one may say, it is very problematic to run into recording speed, and therefore you should not worry about it categorically. Yes, of course, it’s wildly pleasant when, according to benchmarks, everything is so cool, but for a normal person it will be good and comfortable in any situation. Personally (I personally) like controllers from Intel, Marvell, Jmicron and Toshiba. But when buying an SSD, even I am usually more interested in reliability and price rather than controllers.
3) Reliability is a relative thing. In the sense that a lot depends on external factors, and even the most proven pieces of iron can die the death of the brave if their owner is a dunce. For example, drives are traditionally nervous about the quality of the power supply, and if the power supply in the computer is faulty, anything is possible. But you've already read it and you won't miss it. Plus network filter. A real one, not a socket with a light bulb.
Which brands of SSD can you safely buy?
Intel
Intel(very good, so twice)
ADATA
Crucial
Kingston
OCZ
Sandisk
Seagate
Samsung
Silicon Power
Transcend
There are several other manufacturers with smaller calibers. In principle, you can pay attention to them if the seller is reliable, and there will definitely be no problems with returns/replacements. But I wouldn't. Fortunately, the listed brands have models from very different price categories.
4) Important point- guarantee period. On average it is 3 years, but some particularly responsible manufacturers (Intel! Intel!) give five years. The MTBF of an SSD is enormous, from 1 to 2 million hours, so you are unlikely to hit this parameter (well, 114 years may not be enough, but 228 will certainly be enough). If you constantly make backups, even the untimely death of an SSD during the warranty period is unlikely to upset you. And, I repeat, it is necessary to make a backup of the SSD. That’s why they don’t die in parts, like HDDs, but usually all at once. And it is extremely expensive to extract data from there. Although you need to backup both.
So let’s decide on the volume, don’t bother with the controller, choose good brand and see what guarantee period for a specific model. That's all! You will be pleased.
As usual, here are 10 SSD models that you can safely take.
1. Intel SSDSC2BP240G401 710-Series 240 GB(2 million hours between failures, 5 years warranty)
2. ADATA Premier Pro SP920 256 GB(well balanced model, read speed up to 560 MB/s)
3. Samsung 850 Pro 512 GB(for those who need a lot of fast space, writing up to 520 MB/s, reading even faster. 512 MB buffer. But not cheap).
4. SanDisk X300s 256 GB(corporate model with increased daily recording resource, up to 80 GB)
5. Silicon Power Slim S55 240 GB(not the fastest, recording “only” 440 MB/s, but the price is nice).
6. OCZ Saber 1000 240 GB(another fast corporate model. You can rewrite up to 100 GB every day at a speed of 500 MB/s, and at the same time it will work for three years, guaranteed).
7. Kingston SSDNow V300 480 GB(many people wince because of the SandForce controller inside, but the speed is enough. Plus it’s one of the most available options SSD of this capacity).
8. Transcend SSD370 (Premium) 256 GB(not outstanding in speed, but reliable and inexpensive model)
9. Intel DC S3710 Series 800 GB(an extremely reliable model, capable of overwriting almost 17 Petabytes. Petabyte, that’s not a typo. And if you have 90,000 rubles to spare, you simply can’t find a better option).
10. Samsung 850 Pro 128 GB(it costs more than many 256 GB models, but it has the same speed as many of them - 550/470 MB/s. Fans of small but fast ones will appreciate it).
Now you know everything about SSDs. You don't need to read anything else...
I'll write more about memory and HDD soon.
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Nowadays, a solid-state drive is no longer a privilege of expensive laptops, but an almost obligatory component even for models costing 60 thousand rubles. However, if you ask yourself this question, then the most interesting things are yet to come.
As Confucius said: “Once you work on a computer with an SSD, there will be no turning back.” If in the last decade everyone was chasing hundreds and thousands of megahertz, then with the advent of SSD it became obvious that the bottleneck was the drive, not the processor.
If your laptop with a quad-core i7 takes a minute or more to load Windows and launch applications, the problem is definitely with the slow hard drive, and not with the processor. With an SSD, everything starts in a matter of seconds, files are opened and saved instantly. As a result, work becomes much more enjoyable. So let's be honest: the only time you don't need an SSD is if you already have one.
SSDs are expensive, aren't they?
Hard drives are still noticeably cheaper than SSDs based on the price of one megabyte, this is a fact. But in most cases, you don’t need a bulk “solid state”. You can always watch TV series online, store photos in the bottomless storage of Yandex.Disk, Google Drive or Dropbox, listen to music from countless streaming services, domestic or foreign.
So it turns out that often users don’t actually have that much information on their laptop, and the basics can be stored on a fairly inexpensive SSD. True, on gaming laptop It's not that simple anymore. Of course, I would like to install all the toys on a solid-state machine so that the maps in Battlefield don’t take such a painfully long time to load. But, unfortunately, modern games take up too much space to be installed on inexpensive solid-state drives. But there are options, described in the next paragraph.
Where will I store terabytes of photos from my last vacation in Tenerife?
External HDD
And even if your laptop is filled to capacity with media files, this is still not a reason to refuse to purchase an SSD. Even a not very large volume is enough to install an operating system, browser and other essential programs. And then you won't recognize your laptop.
Moreover, it is not at all necessary to give up a hard drive with hundreds of gigabytes of goods acquired through back-breaking labor. Firstly, there are many laptops with space for both a fast solid-state drive and a large hard drive. Secondly, even if you have a super-thin ultrabook, this is not a problem - external hard drives have been on sale for a long time. And even hard drives with Wi-Fi for those who don’t like wires. Or again, you can rent a place in the cloud. Although, if you plan to use it as a balcony or garage, that is, to look only once a year or less often and put everything there that you don’t want to throw away, then it’s better to take an external hard drive.
Can I install an SSD in my laptop?
In most cases, the answer is yes. It’s definitely not possible to install a “solid state” only in laptops in which it is already soldered directly to motherboard. But cases when the laptop already has an SSD are not of much interest to us in this material.
If your laptop has only one slot for storage devices, and it is already occupied by a hard drive, then the best option is to buy a solid-state drive to replace the hard drive, and for the hard drive, purchase a special container with an adapter to turn this hard drive into a convenient external hard drive. This way you solve the problem with both system speed and storing a large amount of data. And, in fact, you have nothing to lose.
One way or another, you will have to start by finding out how many drives you can install in your laptop and what type they are. There are not many variations, but enough to confuse the inexperienced person. Therefore, it is best to search forums on specific models, where people have already figured out which drives can be installed in a particular laptop model.
Which to choose?
Form factor
SSD with M.2 connector (top) and SSD form factor 2.5 inches SATA connector(bottom)
The question of choosing a form factor depends not on you, but on your laptop. Older models only support 2.5-inch drives with a SATA interface. They are not as fast as some modern solid state devices with an M.2 connector. Most often, purchasing them is simply a necessity if the laptop does not have M.2.
However, the performance of a high-quality 2.5-inch solid-state drive is more than enough for everyday needs, and even more so for a person who has never dealt with an SSD before. Moreover, the M.2 connector itself is not an indicator of the drive’s performance, and among SSDs with M.2 there are even slower models.
However, the fastest M.2s are five times faster than standard 2.5-inch ones. But the point here is not even in the name of the connector, but in the data transfer interface. For more fast SSDs indicates the abbreviation PCIe 3.0 (or NVMe), but we will not dwell on such subtleties in detail.
Volume
Anything less than 120 GB is not worth attention at all - nothing will fit there, and you will just experience constant pain. The exception is all sorts of Chromebooks with 32 and 64 GB drives, but often these are not even SSDs, but devices with slow memory and slow controllers that work even slower than hard drives.
You can already live with a 120 GB drive, but only on the condition that you really don’t store a lot of programs and files. Otherwise, it is better to pay attention to the 256 GB models.
Finally, 512 and 1024 GB are desirable figures for many, but the cost of such drives at retail is high, and the surcharge for modifying a laptop with similar ones is even higher. You can even place video games there, or, for example, two operating systems, each with its own set of programs and files, and much more that your imagination is capable of.
Price
Let's get to the unpleasant part. Prices for 256 GB SSDs, be they 2.5” or M.2, start at about 6,000 rubles. 512 GB - already from 10 thousand rubles. Of course, these are starting prices, and, depending on the performance of the drive or simply the arrogance of the brand, they can be one and a half to two times higher for a model of the same volume. Whether a model is worth the money or not - this, unfortunately, can only be found out from reviews or discussions on forums. Or from reviews in stores, if only you know how to read these reviews correctly.
More and more users are purchasing SSD drives for installation in PCs. They are used in parallel with HDD or instead of them. Solid State Drives have many advantages over hard drives. Therefore, you need to know how to choose the right SSD drive for your computer.
What does it represent?
A solid state drive is a non-mechanical storage device. It is intended for installation on PCs, laptops, server equipment and is designed to replace HDDs. An SSD is created based on memory chips that are controlled by a special controller.
Advantages and disadvantages
Advantages:
- high speed of reading/writing data and performance;
- low heat generation and electricity consumption;
- no noise due to the absence of moving parts;
- small dimensions;
- high resistance to mechanical damage(overload up to 1500g), magnetic fields, temperature changes;
- stability of data reading time regardless of memory fragmentation.
Flaws:
- limited number of rewrite cycles (1,000 – 100,000 times);
- high price;
- vulnerability to electrical damage;
- the risk of complete loss of information without the possibility of its recovery.
Main characteristics
If you are buying an SSD to install on your computer, pay attention to its main characteristics.
At the time of buying SSD drive First of all, pay attention to the volume and purpose of use. If you are purchasing it just to install the OS, choose a device with 60 GB or more memory.
Modern gamers prefer to install games on SSDs to increase performance. If you are one of them, then you need an option with a memory capacity of 120 GB.
If you purchase an SSD instead of hard drive, proceed from the calculation of how much information is stored on the computer. But in this case, the capacity of the SSD disk should not be less than 250 GB.
Important! The cost of a solid-state drive directly depends on the volume. Therefore, if your budget is limited, use an SSD to install the operating system and a HDD to store data.
Most modern models SSD drives Sold in a 2.5-inch form factor and built into a protective box. Because of this they look like classic hard disks the same size.
Good to know! To install a 2.5-inch SSD drive into a standard 3.5-inch mount inside a PC case, special adapters are used. Some case models provide sockets for a 2.5-inch form factor.
There are 1.8-inch and smaller SSDs on the market that are used in compact devices.
Connection interface
Solid state drives have several connection interface options:
- SATA II;
- SATA III;
- PCIe;
- mSATA;
- PCIe + M.2.
The most common option is to connect using a SATA connector. There are still SATA II models on the market. They are no longer relevant, but even if you purchase such a device, thanks to the backward compatibility of the SATA interface, it will work with a motherboard that supports SATA III.
When using an SSD with a PCIe interface, you may need to install drivers, but the data transfer speed will be higher compared to a SATA connection.
mSATA models are used on compact devices, but work on the same principle as the standard SATA interface.
M.2 or NGFF (Next Generation Form Factor) models are a continuation of the development of the mSATA line. They have smaller dimensions and greater flexibility for configuration by digital equipment manufacturers.
Read/write speed
The higher this one is, the more productive computer. Average speeds:
- reading 450-550 MB/s;
- recording 350-550 Mb/s.
Manufacturers may indicate not actual, but maximum speed read/write. To find out the real numbers, look online for reviews of the model you are interested in.
In addition, pay attention to the access time. This is the time during which the disk finds the information required by the program or OS. The standard indicator is 10-19 ms. But since SSDs have no moving parts, they are significantly faster than hard drives.
Memory type and runtime to failure
There are several types of memory cells used in SSD drives:
- MLC (Multi Level Cell);
- SLC (Single Level Cell);
- TLC (Three Level Cell);
- 3D V-NAND.
MLC is the most common type, which allows you to store two bits of information in one cell. It has a relatively short resource of rewrite cycles (3,000 - 5,000), but lower cost, due to which this type of cells is used for mass production of solid-state drives.
The SLC type stores only one bit of data per cell. These microcircuits are characterized by a long lifetime (up to 100,000 rewrite cycles), high data transfer rates, and minimum time access. But due to the high cost and small data storage volumes, they are used for server and industrial solutions.
The TLC type stores three bits of data. The main advantage is low production cost. Among the disadvantages: the number of rewrite cycles is 1,000 - 5,000 repetitions, and the read/write speed is significantly lower than the first two types of chips.
Healthy! Recently, manufacturers have managed to increase the lifetime of TLC discs to 3,000 rewrite cycles.
3D V-NAND models use 32-layer flash memory instead of standard MLC or TLC chips. The microchip has a three-dimensional structure, due to which the volume of recorded data per unit area is much higher. At the same time, the reliability of information storage increases by 2-10 times.
The reliability of the solid-state drive depends on the manufacturer. Famous companies produce high-quality devices with subsequent technical and hardware support. Their factories have high requirements, which ensures excellent quality manufactured products.
Modern SSD manufacturers drives: Samsung, OCZ (a division of Toshiba), Kingston, Crucial, Corsair, Plextor, GOODRAM, Silicon Power, Transcend.
TRIM function
Most important additional function for a solid-state drive, this is TRIM (garbage collection). It is as follows.
Information on the SSD is first written to free cells. If the disk writes data to a cell that was previously used, it first clears it (unlike an HDD, where data is written over existing information). If the model does not support TRIM, it clears the cell immediately before writing new information, due to which the speed of this operation decreases.
If the SSD supports TRIM, it receives a command from the OS to delete data in the cell and clears it not before overwriting, but during the “idle” of the disk. This is done in the background. This maintains the write speed at the level specified by the manufacturer.
Important! The TRIM function must be supported by the operating system.
Hidden area
This area is not accessible to the user and is used to replace failed cells. In high-quality solid-state drives it is up to 30% of the device volume. But some manufacturers, in order to reduce the cost of an SSD drive, reduce it to 10%, thereby increasing the amount of storage available to the user.
The other side of this trick is that hidden area used by the TRIM function. If its volume is small, it will not be enough for background data transfer, which is why when the SSD “load” level is 80-90%, the writing speed will drop sharply.
Model overview
Below is a list of several popular models.
| Form Factor | Read/write speed | Those. process |
Weight | ||||
| Kingston HyperX Fury (SHFS37A/240G) |
240 GB | 2,5 inches |
SATA-III | 500/500 Mb/s |
MLC | 20 nm | 90 g |
Over the past few years, SSDs have evolved from expensive drives with a small amount of memory into widely available consumer solutions, and although the price per gigabyte of SSDs is still higher than that of HDDs, many people take SSDs at least for system installation. In this case, a completely logical question arises - how not to get confused in all the variety of solid-state drives and choose the best one? We'll talk about this in this article.
SSD form factor
The first thing you should decide on is the SSD connection type. In the case of inexpensive and (or) old laptops, the choice is unfortunately small: if it has a HDD, then you can always replace it with a 2.5" SSD with a SATA interface connector. Also, if the laptop has a disk drive, it can be replaced with a plug with a SATA interface inside (the whole design is called Optibay): this will allow you not to remove the HDD, that is, there will be two drives in the system.
In the case of newer laptops and some PCs, it is possible to install an M.2 SSD. Unlike 2.5" SSDs, which are connected only via SATA, M.2 can also be connected via PCI-Express bus. PCI-E support is quite clear: SATA3 has a maximum throughput of 500-600 MB/s - this is more than enough for hard drives, but some SSDs can operate at higher speeds, which PCI-E provides. In the case of M.2 there are two options:
- PCI-E 2.0 x2, 8 Gb/s bandwidth, which in practice gives a speed of about 800 MB/s;
- PCI-E 3.0 x4, 32 GB/s bandwidth, which gives a practical speed of about 3 GB/s.
Accordingly, PCI-E SSD with key B and M look like this:
As you can see in the photo above, PCI-E SSD with different keys are not physically compatible, that is, installing an SSD in a slot that is not supported by it will not work.
The variety of M.2 SSDs does not end there - they can also have different sizes. There are three options in total - 2242, 2260 and 2280. The first two digits are the same for everyone - this is the width of the SSD. The second two are the length, respectively. SSD smaller size can be installed instead of a larger one: that is, for example, if there is room on the motherboard for 2280, then 2242 will fit without problems. But if there is no room on the board for only 2242 - 2260, other elements of the board will interfere with it.
Well, finishing with form factors, we should say about SSDs, which will be connected in the most regular slot PCI-Express extension, which is found on almost any PC motherboard: 
Typically, such SSDs are PCI-E M.2 SSDs simply inserted into an adapter board, so in terms of speeds everything is the same as with M.2.
Types of Flash Memory in SSD
The main difference between memory chips in different SSDs is the number of bits that each memory cell can store. There are three types of cells in total:
As you can see, drives with SLC cells (Single-Level Cell) are the fastest and most reliable, but one cell holds only 1 bit of information, so the volume of such drives does not exceed 64 GB. In addition, SLC memory is the most expensive, and for the amount you would have to pay for a 64 GB SSD with SLC, you can get a 500 GB SSD with MLC. Considering that the reliability of SLC for custom use redundant, SSDs with SLC memory are practically not sold on the market, and there is no reason to buy them for a regular PC or laptop.
SSDs with MLC cells (Multi-Level Cell - multi-level cell, although by “many” they mean only two) have significantly lower reliability and several long delays, however, they allow you to write 2 bits into a cell. The price per gigabyte of such SSDs is constantly falling, and the entire range of volumes is available on the market - from 8 GB to 2 TB. These SSDs are well suited for high-performance PCs and laptops, where high speed operation and fairly good reliability are needed (3000 rewrite cycles in the case of a 100 GB SSD will make it possible to record 300 TB of information - to download such a volume from the Internet at a speed of 10 MB/s you will need year!)
TLC (Triple-Level Cell) are the oldest cells that were first used in flash drives and then migrated to SSDs. They have only 1000 rewrite cycles and quite long delays, but at the same time they allow you to write 3 bits per cell and are quite cheap. It makes sense to install such SSDs in simple laptops and PCs, where there is no heavy load on the drive and its operating speed is not important: the main thing is that such SSDs will still be significantly faster than the best HDDs.
There is also an Optane SSD from Intel with new memory 3D-Xpoint, however, they are still sold only as cache memory for accelerating a system with an HDD, which will be worse in terms of speed than installing the system on a full-fledged SSD. Taking into account the fact that such an SSD cache is also very expensive (from $70 for 16 GB) and their support is only available in systems with Intel Kaby Lake(seventh generation of processors Intel Core) - there is no point in buying them yet.
SSD controllers 
Controllers are the “brains” of the SSD; they must quickly process the information they receive and place (or retrieve) it from memory. And if the controller is slow, then the SSD even with the most better memory SLC will operate at the speeds of conventional flash drives. There are quite a lot of controller manufacturers on the market, let’s look at the main ones:
- SandForce- the controller is distinguished by the absence of “external” cache memory, tolerates multi-threaded reading/writing very well, and has the highest (claimed!) speeds of both reading and writing to date. Performance in linear sequential tests and random read/write tests drops by almost a third in occupied areas and does not recover after data is deleted.
- Marvell- according to usage statistics, one of the fastest and relatively inexpensive controllers is “immune” to the degree of data compression, and general speeds drives drop slightly over time.
- Intel- a controller that has proven itself in server applications, where Intel traditionally excels. Not bad in workstation scenarios either. Flaw - low speed recordings, which is practically not noticeable in everyday tasks.
- JMicron- the first generation SSD controller is poorly suited for working with flash memory, has low performance and only 16 KB of cache memory (which leads to its overflow if the load on the disk increases and the system hangs for a minute or two, waiting for the buffer to be cleared). The only advantage of the drives on this controller is the relatively low price.
- Indilinx- a controller adapted for SSD and without the disadvantages of Jmicron. Excellent recording performance is its main feature. Balanced performance (almost the same read and write speed) allows us to recommend drives on this controller for working with large files. Cleaning support is available, but it works less efficiently than in the case of Intel. Performance is highly dependent on storage capacity.
- Samsung- Korean controller, designed taking into account the shortcomings of JMicron. Despite the large cache size, there was no worthy alternative to Indilinx. The system no longer freezes, sequential read/write performance is at the Indilinx level and sometimes even higher, but the problem is with inconsistent writes, the speed of which is not high. The 850 EVO and PRO lines have addressed the issues with slow, inconsistent write speeds, making them one of the best controllers out there.
