For six years, SSD drives have evolved from an expensive toy for the elite, into a thing that should stand on any modern computer. All due to the fact that solid-state drives have become popular due to the high speed of data exchange, quiet operation, shock resistance, compactness, and of course prices that are slowly but constantly decreasing. Today on sale you can find a large number SSD drives  from a variety of brands. To make it easier to focus, we present the ten best SSDs of 2016, which you should pay attention to.

10. Crucial BX200 480GB - $ 120

Crucial BX200 attracts first of all with its price, otherwise it loses almost all competitors, despite all attempts and engineers to increase the speed of data exchange due to caching. This SSD drive can be recommended for upgrading a computer to get rid of the hard drive, or for assembling a relatively inexpensive computer.

9. Crucial MX200 1GB - $ 280

The Crucial MX200 is a fairly high-quality SSD drive, where developers sacrificed the speed of work in favor of proven components that had to be worked with before. The most attractive thing here is the price; one gigabyte of free space will cost approximately 28 cents. In general, a good drive, which, however, loses in data transfer speed, functionality and quality of performance to Samsung, SanDisk and OCZ products.

8. Kingston HyperX Savage 480GB - $ 155

Solid, qualitatively and reliably, Kingston HyperX Savage is made according to this principle. In terms of data transfer speed, this disk is almost as good as Samsung and SanDisk solid state storage. Kingston HyperX Savage which can be recommended to gamers and computer enthusiasts who pay a lot of attention to the appearance of iron.

7. OCZ ARC 100 240GB - $ 80

Although this is a budget drive from OCZ, however, it has good performance, is built from high-quality components and has a warranty of 3 years. An excellent choice for people who decide to try a solid-state drive in action and fear for the safety of their data.

6. PNY CS2211 240GB - $ 70

PNY CS2211 is one of the most affordable, or rather cheap, SSD drives on the market, which at the same time demonstrates a very good speed of data exchange. But there is one big problem, it is very difficult to buy it, all that appears in online stores is bought up in a few hours.

5. Kingston KC400 SSDNow 512GB - $ 165

Kingston KC400 SSDNow is a fantastic SSD drive, which takes first place in data transfer speed in all tests, all thanks to the new Phison S10 memory controller and Toshiba high-speed MLC NAND memory. It can be recommended to install both on new computers and for upgrading old ones, though it will be, it costs a little more than the Samsung 850 Evo.

4. SanDisk Extreme PRO 480GB - $ 190

SanDisk Extreme PRO is the most advanced SSD drive for the consumer market from SanDisk. The manufacturer has made a major bet on reliability, giving a 10-year warranty, so SanDisk is confident in the quality of components used in the manufacture of drives. All complements, though not outstanding, but very decent speed of data exchange.

3. Samsung 850 PRO 1TB - $ 425

Although the terabyte Samsung 850 PRO drive was released, at the beginning of the year, however, it still has competitors in the world of SATA SSD drives. Here, for the first time, 3D V-NAND memory was used on the consumer market drive, and the firmware for the MEX controller of its own production was completely rewritten, which made it possible to achieve a high data exchange rate. If you need a large and fast SSD drive for the SATA connector, then the Samsung 850 PRO will be an excellent choice.

2. Toshiba Q300 480GB (2016) - $ 130

The Toshiba Q300 of 2016, assembled on its own memory controller, boasts a lower value than most competitors, while demonstrating a high rate of data exchange in different modes of operation, without obvious failures. The Toshiba Q300 hard drive is an excellent choice for a relatively budget computer or for a planned upgrade of your system unit.

1. Samsung 850 Evo - $ 155

Samsung 850 Evo with a capacity of 500 gigabytes is probably the best SSD drive you can buy today. Its main advantages are high speed of data exchange and reliability (5 year warranty for itself), all this is complemented by a bunch of technologies designed to increase the service life of the disk and the reliability of data storage. If you want to change your old hard drive or SSD drive, then without hesitation you should stop your owl choice on the Samsung 850 Evo.

Preamble

I do not cease to repeat - in order to make a good choice of technology, it is necessary, at least in general terms, to understand the subject area. Know what characteristics have the equipment you choose. Know how these characteristics affect the operation of machinery.

Purchase SSD drive  the matter is much more complicated than it seems to the uninitiated. A lot of unobvious, hidden under the surface. This article will list the important characteristics of SSD drives. It will be explained how the parameters of an SSD drive affect its consumer quality. The material is large in volume, since the topic is quite complicated.

There are a lot of letters here, but if you have enough patience to read everything to the end, then it will be easier for you to decide which SSD drive is better to buy. But if you do not like to read a lot then wait for a truncated version of this article.

Introduction

SSD is no longer a luxury and becomes a means of data storage. Over the past couple of years, especially during 2013 and the beginning of 2014, the prices for SSD disks have decreased so much that it is already possible to put such a disk in a completely ordinary computer. At the same time, the speed of operation of modern SSD disks is such that their use gives the greatest performance gain in terms of money spent.

For 120 - 150 dollars spent on good SSD   disk, you can get a real increase in performance for more than the same money spent on the processor or RAM.

Even the crisis of 2015-2016 did not affect the availability of SSD drives. In these years, SSD drives cost 2.5 ”HDD, although adjusted for capacity 4 times (128 Gb SSD cost 500 GB HDD). In 2017, SSD drives became a bit more expensive than HDD.

SSD specifications

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

The main characteristics of SSD

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

Manufacturer

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

• Intel. The company together with Micron produces flash-memory. Thus, it makes its disks from its own memory and selects the best copies of the memory for its disks. Not by chance on their discs gives 5 years warranty.
• Micron  (trademark Crucial). The company together with Intel produces flash-memory. Thus, it makes its disks from its own memory and selects the best copies of the memory for its disks. The difference from Intel is that Micron (Crucial) focuses on the budget segment of the market. Lower price, less warranty. But the discs are good, although the speed does not shine.
• Samsung. One of the leaders of the SSD market. And not only in terms of sales, but also technologically. The company itself produces flash-memory, controllers are also their own. The drives are 100% own - and the memory and controllers are all theirs. Though in the budgetary EVO 850 series in some models there can be another's controllers (Phison or Silicon Motion).
• Plextor. Japanese company, famous for its laser drives. In fact, the SSD does not itself - they are made for it by Lite-On. But the wheels are very good. On Marvell controllers. Plextor is not only quality, but also speed.
• Corsair. American company known for high quality of various products - rAM, Power supplies. The company's products are focused on the so-called "enthusiasts", people willing to pay more for higher quality and speed. However, the budget models they can be very average in speed.
• SanDisk. The American company, one of the leaders in the production of flash drives and SSD drives. Toshiba's partner in the production of flash memory chips. Thus, the discs are made from its flash memory.
• Toshiba. The Japanese company, among other things, the manufacturer of flash memory chips. Thus, the discs are made from its flash memory.

SSD Capacity

Manufacturers of SSD drives indicate this difference in the specifications of their drive models. Therefore, before buying a fast disk - carefully read its specifications, perhaps the size you have looked after is not as fast as you expect.

That case when the size matters.

There is another feature associated with the capacity of SSD drives. There are groups of models in capacity, but not all models from this group have the same capacity. Example. Group capacity 120/128 GB. Some models in this group have a capacity of 120 GB, and the other 128 GB. What is the reason?

The fact is that in fact all the disks in this group have a capacity of 128 GB, but on some models, 8 GB is reserved both for leveling the wear of flash memory cells and for replacing broken cells.

Someone from the manufacturers may not be quite sure of the quality and life span used in their flash memory model and therefore makes such a reserve. Someone makes such a stock just for greater reliability. For example, in Intel drives, the quality of flash memory is very high, nevertheless, the company is reinsured by making a reserve of cells.

Disk Controller

The best controllers are considered Marvelland   Samsung MDX.More on controllers later in this article.

Write speed degradation (garbage collection)

Reducing the speed of writing to an SSD disk after it is completely full and after filling it will clear the data. That is, writing to reusable memory blocks. More on this in the section.

Secondary SSD specifications

Hardware encryption  with support for TCG Opal 2.0 and IEEE-1667. This makes it possible to use hardware encryption but manage it from the OS. For example, you can unload the CPU when using Windows BitLocker.

Protection against power loss. Some models of SSD drives are protected against sudden blackouts. Usually, these are simply capacitors, the charge of which is enough for the disc to complete the necessary write operations to the memory cells.

Interfaces

SATA

Today (2014), all SSD drives are available with SATA 3 interface. However, there are still a lot of computers in hand motherboardsah installed controllers SATA 2 (SATA 300) and even SATA 1 (SATA 150). Can I install a new SSD in such a computer?

Sure you may. However, you need to understand that in this case, the new SSD drive will give out real speed well below its passport characteristics.

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

But with SATA 2 controllers, the practical speed is limited to about 270 MB per second. Accordingly, with SATA 1 controllers, it is even lower - less than 150 MB per second. So, if you put a new SSD in old computerthen it will work slower than it can at all.

So for the new SSD drive you need to buy new computer? Not.

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

PCI-express

In addition, now there are SSD models that are made in the form of a PCI-express card, for example    Plextor M6e. So there is no need to buy anything else, just insert the disk board into the PCI-e slot and that's it. In the PCI-e slot, you can also install an SSD disk form factor M.2, but through an adapter card from M.2 to PCI-e.

M.2 (Next Generation Form Factor, NGFF)

Also, a new, faster interface for peripheral devices  - M.2. You can buy an adapter M.2 made on the PCI-express board and then put there an SSD disk with interface M.2. Disc mentioned above    Plextor M6ejust such an option is a PCI-express board with adapter M.2, on which a disk with interface M.2 is installed.

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

Memory

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

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

In the production of SSD drives used flash memory (flash-memory) NAND type.

NAND Flash Memory Manufacturers

Only a few companies make memory for SSD disks - Intel and Micron (total production), Toshiba and SanDisk (total production), Samsung, Hynix.

The first such memory was created by Toshiba in the late 80s of the last century. Thus, it is the oldest manufacturer of NAND flash.

According to the type of wiring of contacts in the microcircuit case and the subsequent access from the NAND flash controller side, it can be divided into two types:

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

Types of NAND flash memory cells

Today (in 2014), NAND flash memory with three types of cells is used in SSDs:

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

The difference between these types is that with an increase in the number of bits stored in one cell, the cost of memory in terms of its capacity decreases. That is, relatively speaking 128 GB of MLC memory cost less than the same 128 GB, but SLC type.

However, you have to pay for everything. As the number of bits per cell increases, the number of write cycles that this cell can withstand decreases. For example, an SLC type memory withstands up to 5,000–10,000 rewriting cycles. And the recording limit for MLC memory is up to 3000 cycles. TLC-type memory has this limit even lower - 1000 write cycles.

That is, with an increase in the number of bits per cell, the lifetime of this cell is reduced. But this increases the recording speed.

In 2017, we can talk about the victorious march of TLC memory. Already probably more than half of all SSD drives are made on this memory.

Basic parameters of flash memory for SSD

The main characteristics of flash-memory for SSD drives are:

1. The number of write cycles that a single cell of this memory can handle. This parameter determines the lifetime and reliability of flash memory.
2. Technical process for which the flash-memory crystal is made.
3. Type of flash memory cells.

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

• Reducing the process reduces the life of the flash memory.
• Increasing the number of bits in a single cell reduces the lifespan of flash memory.

That is, an MLC type memory will have a shorter life span than an SLC type memory. The memory made by the technological process of 25 nanometers will have a lifetime longer than that produced by the technical process of 19 nanometers.

Memory Capacity (Size)

Specified in gigabytes. The feature of SSD is that larger capacity disks give a higher data transfer rate, especially when writing. The difference in write speed between a 120/128 GB and 480/512 GB disks can go up to two or three times.

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

This difference is due to the fact that the SSD disk controller works with all memory crystals simultaneously (in parallel). And in one model of a disk identical crystals of memory are used. Accordingly, the difference in capacity is the difference in the number of crystals. Fewer memory crystals — less paralleling operations — lower speed.

Do not confuse memory crystals and memory chips. In one chip can be from one to four memory crystals. That is, in disks of different capacities, the number of chips may be the same - 8, but the number of crystals will be different.

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

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

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

For example SSD Crucial M500  assembled on 128 bit memory chips. In this line there are 4 models:

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

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

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

All SSD disk controllers use interleaved cells when writing to even out cell wear. For alternation using free memory. Accordingly, the less disk space is occupied by data and programs, the more possibilities the controller has for alternating cells and the longer the memory will live.

Large disk capacity is the easiest way to increase free disk space. Suppose that the programs and data you occupy 100 gigabytes. If it is placed on a 120 or 128 GB disk, then the disk will be almost all busy and few cells will be available for rotation. But if the disk capacity is 240 or 256 GB, then a lot of cells will be available for rotation - more than 50%. Thus, the load on the cells will be much lower and there will be longer and even wear.

Controllers

A computer cannot get direct access to flash-memory, therefore in disks, in addition to memory chips, they install a controller chip as well. These companies produce several chips:

• Sandforce. Now this company is owned by another company - LSI. SandForce controllers, for example SF2881, are the most common. They dominate the budget segment SSD. On these controllers, even Intel releases SSDs (models 520, 530).
• Marvell  - their controllers 88SS9187 and 88SS9174 are used in high-performance SSD drives different manufacturers, in particular Micron (Crucial), Plextor, SanDisk. For example, one of the world's fastest SSD drives - Plextor M5 Pro, Crucial M500, Crucial M550using controllers Marvell88SS9187, 88SS9189. The company released a fast controller for the interface with NVMe support (M.2).
• Indilinx. Now this company belongs to OCZ and the latest controller model is called Barefoot 3. Accordingly, these controllers are mainly used only in OCZ drives.
• LAMD (Link_A_Media Devices). Fast, but rarely used LM87800 controller. For example, it is used in Corsair Neutron drive models. The company bought Korean Hynix and these controllers are used only in conjunction with Hynix flash memory.
• Phison. This company has long been known for its controllers for USB flash drives. Recently, she launched an attack on the SSD market. It offers budget solutions for the production of SSD drives - controller, firmware, board design. Its controllers are used in budget models, for example Corsair LS, SmartBuy Ignition 2.
• Mdx. This controller is designed by Samsung, used in its drives.
• Intel. Intel uses its own controller on some of its SSDs. These are server models S3500, S3700, and also model Intel 730 oriented on business segment of the market.
• Silicon motion. Another company offering budget controllers for SSD. In terms of performance, nothing outstanding.

The controller depends on the various characteristics of the SSD drive. The speed of work, the lifetime of the flash memory, resistance to data corruption.

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

And SandForce controllers have an unpleasant feature - after filling the disk and cleaning it, the recording speed does not return to the original values ​​(when the disks were empty). It also decreases the speed of work with a very full disk. At the same time, SandForce controllers provide high write speeds on easily compressible data, such as texts, documents.

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

Cheap SSD drives

Cheap SSD drives are usually made on SandForce controllers, and the last couple of years Phison has been actively working in this segment.

The reason for this situation is that both LSI (SandForce) and Phison offer complete solutions for the manufacture of SSDs. Not only the controller, but also the firmware to it, as well as the design of the board for mounting the entire filling.

Thus, the manufacturer of the finished discs do not have to do anything except how to unpack the parts on the board and install the board in the case.

TRIM (garbage collection)

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

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

The problem is that operating systems traditionally do not work with the file system in such a way that deleting files clears the contents of blocks on the disk. After all, on the HDD in this was not necessary.

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

Falling write speeds into reusable flash memory blocks can be very high. To values ​​close to the recording speed of HDDs. When testing SSD drives, they often even perform a special test to reduce the write speed in reusable blocks.

To combat this phenomenon, the disk ATA command TRIM has been added to the new OS. Driver file system  When a file is deleted, it sends a TRIM command to the SSD controller. At this command, the SSD disk controller clears the freed blocks of flash memory, but does so in backgroundin between read and write operations.

Using this command allows you to return the full write speed for reusable flash memory blocks. However, not all operating systems support this command. And only relatively recent versions:

• Linux kernel since version 2.6.33.
• Windows 7, 8 and 10.
• Mac OS X since version 10.6.6 (but for this version you need to install the update).

Until now, popular Windows XP (like Vista) does not support this command.

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

There are two models of SSD drives whose speed degradation of reusable blocks is less pronounced than the others:

• Plextor M5 pro.
• Plextor M5S.

The firmware of these disks can partially clean unused blocks without the TRIM command. Restoring the recording speed to higher values, but not to the full nameplate recording speed.

There are models of disks that even after the execution of the TRIM command do not return to the full nameplate write speed.

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

Note!  When using the function it will be impossible to recover deleted files!

SSD drives by manufacturers

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

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

All the rest is quite a big list.

Intel. The company together with Micron produces flash-memory. Thus, it makes its disks from its own memory and selects the best copies of the memory for its disks. Not by chance on their discs gives 5 years warranty. Some models are also on their own controllers - that is, 100% Intel - such models as Intel DC S3500, Intel DC S3700, Intel 730. Intel drives are very good, but the company mainly focuses on the business market segment and therefore its drives are quite expensive.

But its wheels are worth the money. For example, the S3500 and S3700 server SSD drives use not only selective memory, but also features such as protection against power loss, advanced checksum checking for stored data. This makes them very reliable means of data storage.

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

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

Plextor. The Japanese company is famous for its laser drives. In fact, the SSD does not itself - they are made for it by Lite-On. But the wheels are very good. Intel-Micron or Toshiba memory and Marvell controllers are used. Famous model Plextor M5 Pro  despite the fact that it is no longer young, and in 2014 it remains one of the fastest SSD drives. In 2017, the company remains one of the market leaders in the speed of disks with M.2 disks of the M8Pe G (N) series.

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

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

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

SSD life

The time that an SSD drive will work is generally determined by the type of flash memory. That is, what type of cells is used and according to which process technology the memory is made. It has already been written above, the largest resource in SLC type cells, followed by MLC and finally TLC.

What is the limit on the number of write cycles in a practical sense? And how about to estimate the possible lifetime of a disc?

Take a conditional disk that uses the MLC flash-memory produced by the process technology of 19 nanometers. Suppose that the manufacturer of this memory indicates a write limit of 3000 cycles for it. This is an indicator for a good MLC flash memory manufactured using 19 or 20 nanometers technical processes.

On the basis of this memory, a disk with a capacity of 120 GB is made. A limit of 3000 cycles means that you can burn your disc 3000 times. If you fill it up every day, then completely clear it and fill it up again the next, then theoretically the memory will live 3000 days. That is more than 8 years. If you write only 60 gigabytes per day and erase the disc only once every two days, then the lifespan is increased to 16 years.

Of course it's oversimplified. But it is clear that the life of the flash memory is quite large. Even if we take a disk based on TLC flash, with a limit of 1000 recording cycles, this gives a theoretical disc life of at least 3 years, provided that it will be completely filled every day.

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

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

Finally, many disk manufacturers, in the disk specifications, explicitly specify the limits for writing to disk in gigabytes per day. For example, Samsung in the specifications of the disk 840 Pro writes: "5 years of warranty is provided if you write to the disk no more than 40 gigabytes per day.". And the Micron company, for its Crucial M550, indicates a recording limit of 72 terabytes, or about 66 gigabytes per day for three years.

However, in 2015, Samsung on some models of the PRO series gives 10 years warranty.

In 2017, I can say from my own experience - none of the discs that I installed more than 3 years ago have not broken down yet. True, I never put the drive type SmartBuy. Only Plextor, SanDisk, Samsung, Toshiba.

How to extend the life of an SSD drive

Free disk space. Do not “hammer” it completely - try to keep the disk with 20–30 percent of free space. The presence of free space allows the controller to equalize the wear of memory cells. This free space must be unmarked, that is, not assigned to any partition with the file system. By the way, the presence of such an unallocated space allows you to not bother about TRIM.

Uninterrupted power supply.  If you are using an SSD in a regular computer, connect the computer via UPS (UPS). If the SSD is in a laptop, watch the battery status - do not allow the laptop to be turned off due to the complete discharge of the battery. SSD drives do not like a sudden loss of power. If an abnormal power outage on the disk may damage data in flash-memory cells. Alternatively, you can buy a disk model in which there is protection against power loss (Power Loss Protection).

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

But if you install the SSD in a regular computer, then you are "free hands". The least you can do is use a metal adapter c 2.5 "(SSD) to 3.5" (box for disks in the case). On metal adapter heat from the disk will move to the body. However, for discs in a plastic case, a metal adapter is useless.

In the context of cooling, a big plus is the aluminum SSD case. If the disk is made according to the mind, then the metal case is used as a radiator to remove heat from the microcircuits.

In addition, you can put a fan - in many cases even a place is provided for a special fan that blows the disc box. Some cases even have this fan.

No need to defragment. Fragmentation of the file system does not reduce the speed of the SSD. Therefore, doing defragmentation you will not get a win in speed. However, by defragmenting, you will shorten the life of the disk, by increasing the write operations.

Installing an SSD on an old motherboard

You can breathe a second life into your old computer if you replace the HDD with an SSD. All disk operations will be performed in two to three times faster. A computer performs a lot of disk operations - launching the OS, running programs, opening files, editing files, etc.

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

• Buy a SATA 3 controller on a PCI or PCI-e card.
• Buy an SSD disk mounted on a PCI-e motherboard, such as the Plextor M6e.

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

However, an SSD disk mounted on a PCI-e board is generally a good idea, since it will run faster than when connected via a SATA 3 controller.

Common mistakes when using SSD drives

Error one

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

This is done in order to save space on the SSD drive and increase its lifespan by reducing write operations. After all, for example, temporary files folders are permanent write operations.

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

My categorical opinion is that everything related to the OS and programs should be placed on an SSD disk. Working documents also need to be stored on the SSD drive. On the HDD, it makes sense to store only large data - music, movies. Or data that is very rarely used - archives. Only in this case, you get the highest speed from your SSD drive. Do not forget - the main reason for buying an SSD drive is speed! And that means you need to squeeze this speed to the maximum.

Error two

Disk Defragmenter. Out of habit, the rest of the use of HDDs, people defragment and SSD drive. You do not need to do this! The speed of access to arbitrary data blocks in an SSD disk is approximately two orders of magnitude higher than in HDD. Therefore, the fragmentation of data is no longer reflected in the speed of reading this data.

Summary

The main parameters of SSD drives

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

SSD secondary parameters

• Memory type. SLC memory "lives" the longest, MLC and TLC, in descending order, have a shorter lifetime.
• Memory tehnprotsess. Memory crystals created by a technical process of 19 or 20 nanometers have a shorter life expectancy than crystals created by a technical process of 25 nanometers.
• Hardware encryption  with support for TCG Opal 2.0 and IEEE-1667.
• Protection against power loss.

Which SSD drive to choose

Something like this:

• Manufacturer: Intel, Samsung, Plextor, Corsair, Micron (Crucial).
• Memory Type: NAND Flash MLC or TLC.
• Disk capacity: from 240 to 256 GB.

For example, such models: Intel 730, Intel S3500, Plextor M5 Pro, Crucial M550, Samsung 840 Pro. Of these models Samsung 840 Pro  and    Crucial M550  will give the highest write and read speeds to date. A drive Intel S3500  will give the highest guarantee of integrity and data integrity.

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

If it is a gaming computer, then firstly, you need to take a volume of at least 240/256 gigabytes, and secondly, select a speed model. Because a game sometimes takes up to a dozen gigabytes on a disk, and in the process of launching and in the process of playing a large amount of information is read from the disk.

If the computer for video processing means you need a volume of more than 240/256 gigabytes and a model with the highest sequential write and read speeds.

If critical information is stored and processed on a computer that cannot be lost, then apparently the best choice  will be    Intel S3500  or even Intel S3700.

If the SSD is planned to be used with the old OS, for example Windows XP, it makes sense to think about the effect of "speed degradation" and how to avoid it (for more details see section).

Data recovery

SSD drives have one drawback in comparison with HDD drives. In the event of a breakdown, recovering data from a "dead" SSD disk will be much more difficult, and more often than not, impossible.

This is due to the fact that physically, data fragments are stored in different cells and even in different flash memory chips. And only the disk controller "knows" how to get complete data from this "porridge". And the loss of part of the cells, especially those where the service information is stored, can lead to the impossibility of data recovery.

There is another feature. Even on a working SSD, recovering previously deleted files may not be possible. If the TRIM function is enabled for the disk, then the controller will delete the data of the deleted files.

On HDD drives  Deleted file data is not destroyed until space is required for new files. And this makes it possible to recover deleted files (not always, but often).

So, follow the most important computer rule - need to make important data copies. This rule, however, applies generally to all types of drives, and not just to SSD. Any disk can die at any time.

Update 2015

In rubles, SSDs began to cost more and plus a general crisis - this is bad news.

The good news is that SSD drives have appeared with a 10-year warranty - these are some models Samsung series  850 Pro. And even Intel on its budget series 535 gives 5 years warranty. Given that the smallest disks (120 GB) of these companies are already in the region of $ 100.

Prices (dollar) are declining, productivity rises.

An interesting five of the number of inexpensive SSD drives, at the end of 2015 (from the Yulmart range) in order of price increase:

• Samsung 650 MZ-650120Z
• SanDisk Ultra II
• Samsung 850 EVO Series, MZ-75E120BW
• Intel 535, SSDSC2BW120H601
• Samsung 850 PRO Series, MZ-7KE128BW

Update 2016 year

The good news is that SSD drives that use TLC memory can have a lifetime comparable to drives on MLC memory.

This was made possible by the development of a new algorithm for removing the signal from memory cells - LDPC decoding. Today (in 2016) there are three controllers that support this algorithm:

• Samsung MGXSSD drives Samsung EVO  750 and 850.
• Marvell 88SS1074SSD drives Plextor M7V.
• Silicon motion SM2256

If you believe the tests for resistance to memory wear, the Samsung EVO 850 and Plextor M7V discs show very impressive results. At the level good drives  with MLC memory.

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

A drive Samsung EVO 850  (250 GB) gives speed (measured in the Samsung proprietary program):

• On the controller SATA 2 (Intel ICH9): 268 MB / s read and 250 MB / s write. This speed is confirmed and measured in Ubuntu Linux.
• On the SATA 3 (Intel) controller: 540 MB / s read and 505 MB / s write.

On SATA 2, the speed practically rests on the limit of the SATA 2 standard itself. On SATA 3, the reading speed also rests on the standard limit. And at the same time, Samsung gives 5 years warranty for discs of the line EVO 850. And it turns out extremely fast and very reliable disk.

Update 2017 year

A lot of SSDs of M.2 format appeared on sale, at prices comparable to the 2.5 "SATA format. But more importantly, there were motherboards with an M.2 connector.

However, you need to make a clarification. Not all M.2 format disks can provide read and write speeds significantly higher than via SATA III, that is, significantly higher than 570 MB per second. There are models that, having the format M.2, nevertheless give speed at the level of only SATA III.

The speed closer to 1 GB per second (or higher) depends on whether the disk and the motherboard support NVM Express technology.

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

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

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

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

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

In addition, to support NVMe you need to use a fairly recent version of the OS. Windows out of the box supports NVMe since version 8.1. For Windows 7, you need to install the update and this is not trivial, because the driver needs to be integrated into the installation image. Microsoft has a manual. In this topic there is another instruction in Russian.

On Linux, you must use kernel version 3.13 19 or higher.

What does using an SSM disk with NVMe support? At a minimum, today, it is about two times higher speed, compared with SATA III. And in read mode, the speed is already 3-4 times higher than through SATA III. And over time this gap will increase. So that makes sense to bother.

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

Ivan Sukhov, 2014, 2015, 2016, 2017 .

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Different SSD: is there a difference? Year 2016

I.N. 10/15/2016 09:00 Page: 1 of 5  | | print version | | archive

• Page one:  Entry, a little harsh reality: the race for extreme speed and kopek
• Page 2:  Testing participants
• Page 3:  Configuration, booth and software, performance testing: installing games
• Page four:  Performance testing: running games, copying operations with different file types
• Page five:  Performance testing: mixing, anti-virus checking, conclusion

Introduction

As part of the material " Different SSD: is there a difference?», In which several models of SSD and HDD of various classes were tested, using the example of real user operations we demonstrated the differences between these devices. Almost a year and a half has passed since the publication - a considerable period by the standards of the computer industry. What has changed during this time? Yes, almost everything. Prices - went down. The range is almost completely shaken up by manufacturers, due to lower prices and the need for an adequate (new pricing policy) cost reduction. The term “budget class” is now meant to be a configuration on TLC NAND, and to find something in the initial lines of store price lists based on MLC NAND memory is a real problem. The class of solutions of the flagship level, the one we saw him about a year and a half ago, is on the verge of extinction. Now, “flagship” means a solution not of the 2.5 "form factor with SATA 6 Gb / s interface, but of the M.2 form factor with PCI-Express 3.0 x4 interface. A good example of this is the Toshiba OCZ series of actions in recent months: OCZ Vector 180 (2.5 "SATA) is discontinued, Toshiba OCZ RD400 (PCI-E 3.0 x4) is now the flagship, the OCZ Vertex 460A is replaced with 19 nm memory by Vertex 500 (Toshiba OCZ VT500) on a cheaper 15 nm memory, and now the lower price segment is not a relatively new Trion 150 (with 480 GB or more left), and recently announced TL100which is based on an even more simplified platform than the Phison S10. In other words, if earlier manufacturers were maneuvering in a relatively narrow framework of one type of MLC NAND memory and one form factor, then in 2016 there was more room for their maneuvers, and the “step to the masses” of PCI-Express 3.0 and NVMe interfaces further expanded . But is there any difference between them in practice? As the practical experience of users shows, the situation with work and full-fledged loading of current capacities is still rather bleak today. Thanks to our regular partners, the Regard store and manufacturing companies, we will once again clarify the situation by comparing different models  drives among themselves.

120 GB SmartBuy Splash SSD Drive Review and Testing (SB120GB-SPLH-25SAT3) Trademark  SmartBuy continues to amaze. Most recently, we tested the SmartBuy S11-2280T, which has no analogues at all (this is the only solution on the Phison PS3111-S11 controller), and now another original drive appeared in its product range, called the SmartBuy Splash. And it is also based on an exotic controller - this time Marvell 88NV1120, which is no longer found among the models represented in the domestic retail sector.

A little harsh reality, kicking marketing, or a materiel, too, need to know

Extreme speed race

“Guys, no offense, but I understand why Russia is at a dead end because of experts like you.”
User's reaction to the advice of forum members not to try
collect a RAID array from two Samsung SM951 on LGA 1151.

I quoted this quote from my personal communication experience. Alas, exactly like this: people think of sculpt wonderful constructions without being bothered with the analysis of technical essence. Then they try to make this “Frankenstein” work with various “shaman dances”, arguing with others and not believing that such a plan even technically (not to mention the financial side of the issue) is nonsense. And having forced this construction to give signs of life, users will be surprised to find out that the result does not meet their expectations and ... again they begin to search for the guilty.

Specifically, the user tried to assemble a “zero” level RAID array from two solid-state drives with a PCI-E 3.0 x4 interface on a motherboard based on the Intel Z170 chipset. The bottom line is that he wanted to install both SSDs into connectors connected to the Intel Z170. Studying the block diagram of this chipset will show the unrealizability of the dream about the possibility of obtaining reading speeds in the region of 4.2 GB / s (summing up the possibilities of two SM951 on linear operations).

The fact is that the system logic set itself communicates with the processor via the third version of the Direct Media Interface bus (DMI), which is technically a modified combination of four PCI-Express 3.0 lanes with an appropriate bandwidth of about 3.93 GB per second. Moreover, a part of this bandwidth is used for the needs of the peripherals - the network controller, SATA- and USB-ports and others.

The only solution in the case of the LGA 1151 is the installation of a PLX type switch chip, which connects to the CPU and uses lines from it, but such boards are very expensive due to the cost of such an engineering solution. In terms of the numbers on the price tags, they are actually already beginning to intersect with the LGA 2011-v3 platform, where there is no such problem simply because there are more PCI-Express lines moving away from the processor (from 28 to 40, depending on the CPU model, against 16 for the LGA 1151).

So for what manufacturers install two (or even more) connectors M.2 on motherboards with a LGA 1151 processor socket? The answer is simple: this is great for separate use of drives, when the call goes to only one SSD, and not all at the same time; to install other expansion cards (you can already purchase, for example, Wi-Fi-adapters). No one has canceled the fact of the existence of such SSDs, such as the recently introduced Intel SSD 600p, the modification of which with a capacity of 128 GB provides only up to 770 MB / s for reading and 450 MB / s for writing. That, by the way, is comparable to the two-year-old Plextor M6e with two lines of the PCI-E interface (and still version 2.0).

And besides the actual load, there is also the so-called “service traffic”, which is always there, as a result of which the actual throughput is lower. And, as practice shows, in reality, the LGA 1151 manages to get no more than 3.4-3.5 GB per second, and even those practically in “laboratory conditions” - while minimizing the load on all other system elements and carefully selecting the configuration of the test system. The most realistic are altogether 3.1-3.2 GB.

But one option for LGA 1151 systems is still there: install a PCI-E SSD so that they are connected separately to the processor and to the set of system logic. In this case, only the version of the software assembly will be available operating system, but this is actually unprincipled for one simple reason: in principle, there are no RAID controllers on consumer-grade motherboards.

Yes, exactly: all operations on “consumer” motherboards are performed by the driver at the software level using CPU resources. This type of software array even has the unofficial name “FakeRAID”. The real RAID controller includes its own microprocessor (often with considerable heat generation), a cache memory, a power supply circuit to protect data in the event of an unplanned power outage, and a number of binding elements.

The total cost of such a device is higher than that of most motherboards, not to mention the system logic set itself, and therefore the models like ASRock Z87 Extreme11 / acwhere LSI SAS 3008 and LSI SAS 3x24R are applied together with flash memory, are a kind of exclusive.

In pursuit of a penny

The second half of 2015 - the beginning of 2016 was marked by the fact that the TLC NAND memory has become a truly mass phenomenon in solid-state drives. Samsung lost its “monopoly”, and almost immediately two duos stood out against each other: Toshiba memory with Phison controllers and SK Hynix memory with Silicon Motion controllers.

More famous brands like Kingston, Toshiba OCZ, Corsair and a number of others made a bid for the first duet. The second in the decisions of more or less popular brands turned out to be only in the ADATA assortment, all the rest - a lot of Chinese and little-known companies (and not only here).

Recently, a flash layout with a vertical layout developed by Micron and Intel (IMFT) took place on the scene. In fact, only one drive on it — the Crucial MX300 — is more or less fully present on the market, but the existing layout will not change as a whole. and here - Toshiba and Western digital  (SanDisk) are preparing their 3D V-NAND.

Despite the apparent opposition, these platforms are very close both in terms of the marketing component and the hardware ideology. Drives based on them are positioned on this moment  as a solution of primary and secondary level, and the essence of their work is virtually identical.

With the fact that TLC NAND has a lower cost in production, it also has its drawbacks. In particular, this is a rather slow memory, and in write operations its level of speed does not hold water. So that such drives could offer decent performance, a trick is applied: part of the memory array works in the “accelerated” recording mode (sometimes called “pseudo-SLC”).

As a result, modern models on TLC NAND, with rare exceptions, even being of small size (~ 120-128 GB) carry in their official specifications an indication of write speeds of about 400-550 MB / s - precisely thanks to the SLC mode.

But the amount of data that the drive is able to record at such a high speed is usually small and, depending on the size of the SSD, it can start with about 2 GB for the youngest modifications.

Another thing is that such behavior is not always striking simply because copying really large amounts of data is a situation that does not occur so often. It is not at all pleasant to observe the copying speed almost at the level of quite old HDD models.

The first “step” is Windows caching. The second is the SLC cache. Bottom "shelf" - the real speed of the Zenith R3 120 GB outside the SLC-cache.

In fact, another scenario is quite realistic, in which the lack of an SLC buffer and low speed  recording outside of it: installing games with a large amount of space.

In general, solid-state drives on TLC NAND look optimal in large volumes: the pure amount due to the volume becomes redundant, and the size of the SLC buffer (which is usually specified as a percentage of the SSD volume) is quite large. Yes, and the memory array itself is typed with such a number of NAND crystals that the write speed beyond the SLC buffer increases to decent values. For example, the capacity of planar TLC NAND crystals produced by Toshiba, SK Hynix and Micron is now 128 Gbps, it’s easy to calculate that to build a 128 Gb array you need 8 crystals, and an array of 512 Gb is already typed with 32 crystals.

By the way about the resource. This is another cornerstone of knowledge of the materiel. In fact, contrary to popular belief, a resource is expressed not only by a numerical indicator (how much data can be written to the drive before the first failures), but also by the safety of this data. How is data stored in flash memory? They are stored in the cells in the form of charge, and there is a physical process such as “charge transfer” to neighboring cells. In the end, the memory cell simply stops reading correctly. And the more memory cells are worn out, the more actively and quickly this process takes place. The newly recorded data can be perfectly read, but after a while the problems begin.

To solve this problem, engineers are actively developing new error correction algorithms, but this only pushes the bar away when read from a memory cell becomes undecipherable, in other words, “garbage”. At some point, the controller's firmware may decide to rewrite hard-to-read data to “freshen up” the charge, but “thanks to the“ wear leveling ”algorithms, the new cells where the data will be transferred with high probability are no better. And at some point, as the cells wear out, the loss of charge by the cells will become just an avalanche.

Key here: time. This is where the overwhelming majority of wear tests are carried out, which are carried out by various publications and individual enthusiasts: the newly recorded data can be read perfectly, but after a while (a week, two, three) it may be different, especially if the memory array is already worn out. And this is the main difficulty: a full-fledged correct test will last too long. Not to mention the classics of statistics, the notion of “representativeness of the sample”: as a rule, one or two samples are tested, and not different from several batches. In other words, you can stumble on both instances with flash memory from an unsuccessful batch, and on drives, which have been hit by an exceptionally successful batch of flash memory. Once again, we emphasize that the term “time” means a really noticeable period, and not several days (as some Internet resources raised panic). Timing issue reviewed in this material.

And the type of memory itself is not a sentence yet. In fact, the specific features of individual controllers and platforms in general have a significant impact on the resource of the drive. The most famous example of the latter is the Silicon Motion SM2246XT controller. It has such a property: it behaves well only if there is at least 10% of free space on the drive, otherwise WA (Write amplification, otherwise I have seen WA ~ 1300-1500 for some samples) and the drive in literally dies after several months of operation. And the fact that paired with this controller is used MLC NAND (TLC is not supported SM2246XT), it does not become easier. On the other hand, SandForce controllers disliked by many, due to the data compression implemented in them, in some conditions (for example, in office work) can ensure a twofold superiority in resource compared to other controllers with the same flash memory.

ASUS GTX 1060 for 17 tr. in Citylink

More and more users are buying SSD drives for installation on a PC. They are used in parallel with or in place of the HDD. Solid state drives have many advantages over hard drives. Therefore, you need to know how to choose the SSD drive for the computer correctly.

What is it like?

A solid-state drive is a non-mechanical storage device. It is designed for installation on PCs, laptops, server hardware and is designed to replace HDD drives. SSD is created on the basis of memory chips that are controlled by a special controller.

Advantages and disadvantages

Benefits:

• high data read / write speed and performance;
• low heat generation and power consumption;
• no noise due to the lack 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.

Disadvantages:

• limited number of rewrite cycles (1 000 - 100 000 times);
• high price;
• exposure to electrical damage;
• risk of complete loss of information without the possibility of its recovery.

Key Features

If you buy an SSD for installation on a computer, pay attention to its main characteristics.

When buying an SSD drive, first of all pay attention to the volume and purpose of use. If you purchase it only for an OS installation, choose a device with a memory capacity of 60 GB or more.

Modern gamers prefer to install games on solid-state drives to increase performance. If you are one of them, then you need a variant with a memory capacity of 120 GB.

If you purchase a solid-state drive instead hard drive, proceed from the calculation of how much information is stored on the computer. But in this case, the capacity of the SSD drive should not be less than 250 GB.

Important! The cost of a solid-state drive is directly dependent on the volume. Therefore, if your budget is limited, use SSD to install the operating system, and HDD to store data.

Most modern models of SSD drives are sold in a 2.5-inch form factor and built into a protective box. Because of this, they look like classic hard drives  same size.

Good to know! To install a 2.5-inch SSD drive in a standard 3.5-inch mount inside the PC case, special adapters are used. In some models of cases provided a slot under the form factor of 2.5 inches.

There are 1.8-inch and smaller solid-state drives on the market, which 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 the SATA connector. There are still SATA II models on the market. They are no longer relevant, but even if you purchase such a device, due to the backward compatibility of the SATA interface, it will work with motherboardsupporting SATA III.

If you use a solid-state drive with a PCIe interface, you may need to install drivers, but the data transfer rate will be higher compared to the SATA connection.

The mSATA models are used on compact devices, but work on the same principle as the standard SATA interface.

Models M.2 or NGFF (Next Generation Form Factor) is a continuation of the development of the mSATA line. They have smaller dimensions and greater possibilities for layout by manufacturers of digital technology.

Read / write speed

The higher this is, the more productive the computer. Average speeds:

• reading 450-550 Mb / s;
• recording 350-550 Mb / s.

Manufacturers can specify not the actual, but the maximum read / write speed. To find out the real numbers, look on the Internet for reviews and reviews of the model you are interested in.

In addition, pay attention to the access time. This is the time for which the disk finds the required program or OS information. The standard rate is 10-19 ms. But since SSDs have no moving parts, this is significantly faster than hard drives.

Type of memory and time 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 that allows you to store two bits of information in one cell. It has a relatively small resource rewriting cycles (3 000 - 5 000), but less cost, due to which this type of cells is used for mass production of solid-state drives.

The SLC type stores only one data bit in a single cell. These chips are characterized by a long lifetime (up to 100,000 rewriting cycles), high data transfer speeds, and minimal access times. But because of the high cost and small amounts of data storage, they are used for server and industrial solutions.

The TLC type stores three data bits. The main advantage is low production cost. Among the shortcomings: the number of rewriting cycles of 1,000 - 5,000 repetitions, and the read / write speed is significantly lower than the first two types of chips.

Useful! Recently, manufacturers have managed to increase the lifetime of TLC discs to 3,000 rewriting cycles.

In 3D V-NAND models, 32-layer flash memory is used instead of standard MLC or TLC chips. The microchip has a three-dimensional structure, so that the amount of recorded data per unit area is much higher. This increases the reliability of information storage by 2-10 times.

From the manufacturer depends on the reliability of the solid-state drive. Eminent companies produce high-quality devices with subsequent technical and hardware support. Their plants have high requirements, which ensures excellent quality of products.

Modern manufacturers of SSD drives: Samsung, OCZ (a division of Toshiba), Kingston, Crucial, Corsair, Plextor, GOODRAM, Silicon Power, Transcend.

TRIM function

The most important additional feature for a solid-state drive is TRIM (garbage collection). It consists in the following.

Information on the SSD is first recorded in the free cells. If a disk writes data to a cell that was previously used, it first clears it (unlike HDD, where data is recorded over existing information). If the model does not support TRIM, it clears the cell immediately before recording new information, because of which the speed of this operation drops.

If the solid-state drive supports TRIM, it receives a command from the OS to delete the data in the cell and clears them, not before overwriting, but during an “idle” disk. This is done in the background. It supports write speed on specified by the manufacturer  level

Important! The TRIM function must be supported by the operating system.

Hidden area

This area is not available to the user and is used to replace broken cells. In high-quality solid-state drives, it is up to 30% of the volume of the device. 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 flip side of this trick medal is that the hidden area is used by the TRIM function. If its volume is small, it is not enough for background data transfer, which is why the recording speed will drop dramatically at the “load” level of SSD 80-90%.

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   an inch	SATA-III	500/500   Mb / s	MLC	20 nm	90 g