ssd technology. SSD Solid State Drive. Impossibility of recovering deleted information

Preamble

The article is updated every year, so check back here from time to time. Some of the information that was relevant in 2014 is no longer relevant in 2019. Pay attention to the notes in the text of the article and read the updating sections at the end of the article.

I keep repeating - 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 the technique you choose has. Know how these characteristics affect the operation of the technique.

Buying an SSD drive is a lot more complicated than it seems to the uninitiated. A lot of non-obvious, 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 complex.

There are a lot of letters here, but if you have the 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 don't like to read a lot then wait for a truncated version of this article.

Introduction

SSDs are no longer a luxury and are becoming a storage medium. Over the past couple of years, especially during 2013 and early 2014, the prices of SSD drives have dropped so much that you can already put such a drive in a completely ordinary computer. At the same time, the speed of modern SSD drives is such that their use gives the greatest increase in performance in terms of the money spent.

For $120 - $150 spent on a good SSD drive, you can get more real performance gains than for the same amount of money spent on a processor or RAM.

Even the crisis of 2015-2016 did not affect the availability of SSD drives. In these years, SSD drives cost at the level of 2.5 "HDD, although adjusted for capacity by 4 times (128 Gb SSD cost at the level of 500 Gb HDD). In 2017, SSD drives became a little more expensive relative to HDDs.

Specifications of SSD drives

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

Main characteristics of SSD

These are the SSD parameters that have the greatest impact on the consumer quality of drives.

Manufacturer

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

• Intel. The company, together with Micron, releases flash-memory. Thus, it makes its disks from its own memory and selects the best memory instances for its disks. It is no coincidence that it gives a 5-year warranty on its discs.
• Micron(trademark Crucial). The company, together with Intel, produces flash-memory. Thus, it makes its disks from its own memory and selects the best memory instances for its disks. The difference from Intel is that Micron (Crucial) focuses on the budget segment of the market. Lower price, shorter warranty period. But the discs are good although they do not shine with speed.
• Samsung. One of the leaders in the SSD market. And not only in terms of sales, but also technologically. The company itself produces flash-memory, controllers are also their own. Disks are 100% own - and memory and controllers, all their own. Although in the budget EVO 850 series, some models may have foreign controllers (Phison or Silicon Motion).
• Plextor. A Japanese company famous for its laser drives. In fact, the SSD is not made by itself - Lite-On manufactures them for it. But the wheels are very good. On Marvell controllers. Plextor is not only about quality, but also about speed.
• Corsair. The American company is known for the high quality of various products - RAM, power supplies. The company's products are aimed at the so-called "enthusiasts", people who are willing to pay more for higher quality and speed. However, their budget models can be very average in speed.
• SanDisk. American company, one of the leaders in the production of flash drives and SSD drives. Partner of Toshiba in the production of flash memory chips. Thus, disks are made from their flash memory.
• Toshiba. A Japanese company, among other things, a manufacturer of flash memory chips. Thus, disks are made from their flash memory.

SSD disk 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 at is not as fast as you expect.

The case when size matters.

There is another feature associated with the capacity of SSD drives. There are groups of models by capacity, but not all models in this group have the same capacity. Example. Group capacity 120/128 GB. Some models in this group have a capacity of 120 GB, while others 128 GB. What is it connected with?

The fact is that in fact all disks of 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 failed cells.

Some manufacturers may not be completely sure of the quality and lifetime of the flash memory used in their model and therefore make 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 reinsures itself by making a reserve of cells.

The controller used in the drive

The best controllers are Marvell and Samsung MDX. More on controllers later in this article.

Write speed degradation (garbage collection)

Decreased write speed to an SSD drive after it is full and data will be deleted after it is full. That is, writing to reusable blocks of memory. More about this in the section.

Secondary characteristics of SSD

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, it will be possible to offload the CPU when using Windows BitLocker.

Power loss protection. Some models of SSD drives have protection against a sudden blackout. Usually these are just capacitors, the charge of which is enough for the disk to complete the necessary write operations to memory cells.

Interfaces

SATA

Today (2014), all SSD drives are produced with SATA 3 interface. However, there are still many computers on hand in which SATA 2 (SATA 300) and even SATA 1 (SATA 150) controllers are installed on motherboards. Is it possible to install a new SSD drive in such a computer?

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

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

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

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

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

PCI-express

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

M.2 (Next Generation Form Factor, NGFF)

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

The new M.2 (Next Generation Form Factor, NGFF) interface is essentially a PCI-express bus, only the connector has been changed - it is adapted not for expansion cards, but for small devices. SSD drives in the M.2 form factor are already on sale. This interface should give a data transfer speed higher than the practical limit for SATA 3 - 570 MB per second. The M.2 interface specification assumes the use of 4 PCI-express lanes. For M.2 form factor SSDs, 2 PCI-express lanes are used, so theoretically the speed of data exchange 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 in blocks. Whereas in NOR each cell is processed individually. NAND memory has a longer access time to memory cells, but is much cheaper to manufacture.

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

Manufacturers of NAND flash memory

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

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

According to the type of pinout in the microcircuit package and subsequent access from the controller side, NAND flash is divided into two types:

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

Types of NAND Flash Memory Cells

Today (in 2014), SSD drives use NAND flash memory with three types of cells:

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

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

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

That is, with an increase in the number of bits per cell, the life of this cell is reduced. But at the same time, the write speed increases.

In 2017, we can talk about the triumphant 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 in this memory can withstand. This setting determines the lifetime and reliability of the flash memory.
2. The process by which the flash-memory crystal is made.
3. Type of flash memory cells.

The second and third flash parameters directly affect the first parameter. The dependency is the following:

• Reducing the process technology reduces the life of flash memory.
• Increasing the number of bits in one cell reduces the life of flash memory.

That is, MLC type memory will have a lifetime less than SLC type memory. Memory manufactured using the 25nm process will have a longer lifespan than one manufactured using the 19nm process.

Capacity (size) of memory

Specified in gigabytes. A feature of SSDs is that larger-capacity drives provide greater data transfer speeds, especially when writing. The difference in write speed between a 120/128 GB and 480/512 GB drive can be up to two to three times.

For example, a disk with a capacity of 120/128 GB can give a maximum recording speed of less than 200 MB per second, and a disk of the same model, but with a capacity of 480/512 GB, will give a write 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 the same disk model, the same memory crystals are used. Accordingly, the difference in capacity is the difference in the number of crystals. Fewer memory chips - less parallelization of operations - lower speed.

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

SSD drive manufacturers list this write speed difference in their drive model specifications. Therefore, before buying a fast disk, carefully read its specifications, perhaps the size that you have looked at is not as fast as you expect.

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

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

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

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

As you can see, the difference in write speed between the younger and older models is more than three times. Although in all these are the same disks. Except for the number of memory crystals. By the way, Crucial in its 2014 model M550 uses crystals of different bitness. 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 younger and older models is reduced.

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

All SSD controllers use cell striping when writing to even out cell wear. Free memory is used for striping. Accordingly, the less the disk is occupied with data and programs, the more opportunities 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. Let's assume that programs and data occupy 100 gigabytes. If this is placed on a 120 or 128 GB disk, then the disk will be almost completely occupied and few cells will be available for striping. But if the disk capacity is 240 or 256 GB, then a lot of cells will be available for striping - more than 50%. Thus, the load on the cells will be much lower and there will be longer and more even wear.

Controllers

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

• SandForce. Now this company belongs to another company - LSI. SandForce controllers such as the SF2881 are the most common. They dominate the budget SSD segment. On these controllers, even Intel produces SSD drives (models 520, 530).
• Marvell- their controllers 88SS9187 and 88SS9174 are used in high-performance SSD drives from different manufacturers, such as Micron (Crucial), Plextor, SanDisk. For example, some of the fastest SSD drives in the world - Plextor M5 Pro, Crucial M500, Crucial M550, use controllers Marvell88SS9187, 88SS9189. The company has also released a fast controller for the NVMe (M.2) interface.
• Indilinx. This company is now owned by OCZ and the latest controller model is called Barefoot 3. Accordingly, these controllers are mainly used only in OCZ drives.
• LAMD (Link_A_Media Devices). A fast but rarely used LM87800 controller. For example, it is used in Corsair Neutron drive models. The company was bought by the Korean Hynix and these controllers are used only in tandem with Hynix flash memory.
• Phison. This company has long been known for its controllers for USB flash drives. Recently, it has launched an attack on the SSD market. It offers low cost solutions for SSD production - controller, firmware, board design. Its controllers are used in budget models, such as Corsair LS, SmartBuy Ignition 2.
• MDX. This controller is designed by Samsung and is used in its drives.
• Intel. In some models of its SSD drives, Intel uses its own controller. These are server models S3500, S3700, as well as the Intel 730 model focused on the business segment of the market.
• Silicon Motion. Another company offering budget controllers for SSDs. In terms of performance, nothing outstanding. However, companies such as Intel and Micron are using Silicon Motion controllers in their very successful 2018 models, the Intel 545s and Crucial MX500, which show high read and write speeds.

Different characteristics of the SSD drive depend on the controller. Speed, flash life, data corruption resistance.

For example, Marvell controllers give 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 under conditions of a large number of parallel requests (server load model).

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

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

Inexpensive SSD drives

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

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

Thus, the manufacturer of ready-made disks does not need to do anything except to desolder the parts onto the board and mount the board into the case.

TRIM (garbage collection)

SSDs have an important difference from HDDs that affect write speed. In the HDD, the recording is performed "over" the old data. Disk blocks that previously contained data and then that data was deleted are simply marked as free. And when you need to write, the HDD controller immediately writes to these free blocks.

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

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

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

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

To combat this phenomenon, the disk ATA TRIM command has been added to new operating systems. The file system driver sends a TRIM command to the SSD controller when a file is deleted. On this command, the SSD controller cleans up the freed flash memory blocks, but does it in the background, between read and write operations.

Using this command allows you to return the full write speed for reused blocks of flash memory. However, not all operating systems support this command. But 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 this version requires an update).

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

A workaround for older operating systems is to use third-party programs. For example, this can be the hdparm program (version 9.17 and higher) or proprietary programs from the SSD manufacturer, such as Intel SSD Toolbox.

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

• Plextor M5 pro (old model, discontinued).
• Plextor M5S (old model, discontinued).
• Intel 545s (2018 model).

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

These are certainly not the only models that can independently collect "garbage". Over time, there are more such models, because successful solutions are replicated by other manufacturers.

There are disc models that, even after executing the TRIM command, do not return to full rated 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 manufacturer

Personally, I divide all manufacturers of SSD drives into two categories - the big eight and everyone else. The Big Eight are Intel, Plextor, Corsair, Samsung, Micron (under the brand name Crucial), Toshiba, SanDisk, Hynix. Companies that sell good and great SSD drives. Each of them has its own advantages, for example, Intel, Samsung, Toshiba, SanDisk, Hynix 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 from any of these seven companies without going into details.

All the rest is a pretty big list.

Intel. The company, together with Micron, releases flash-memory. Thus, it makes its disks from its own memory and selects the best memory instances for its disks. It is no coincidence that it gives a 5-year warranty on its discs. Some of the models are also on their own controllers - that is, 100% Intel - such models as Intel DC S3500, Intel DC S3700, Intel 730, Intel 545s, Intel 760p. Intel's drives are very good, but the company mainly targets the business segment of the market and therefore its drives are quite expensive.

But her CDs are worth the money. For example, server SSDs DC S3500 and S3700 use not only selected memory, but also features such as power loss protection, extended checksum verification for stored data. This makes them very reliable storage media.

Micron(trademark Crucial). The company, together with Intel, produces flash-memory. Thus, it makes its disks from its own memory and selects the best memory instances for its disks. The difference from Intel drives is that Micron (Crucial) focuses on the budget segment of the market. Uses his memory and Marvell controllers. In 2014, the company releases a disc that can become a new hit (like M4) - Crucial M550, Crucial MX500.

Samsung. One of the leaders in the SSD market. And not only in terms of sales, but also technologically. The company itself produces flash-memory, controllers are also their own. Disks are 100% own - and memory and controllers, all their own. As of the first half of 2014, the model Samsung 840 Pro it is the fastest SSD drive in the consumer segment of the market (drives for general computers). The speed of this drive is already exhausting the capabilities of the SATA 3 interface. New successful models are Samsung 850 and 860 EVO.

Plextor. The Japanese company is famous for its laser drives. In fact, the SSD is not made by itself - Lite-On manufactures them for it. But the wheels are very good. Uses Intel-Micron or Toshiba memory and Marvell controllers. 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 terms of drive speed with the M.2 drives of the M8Pe G(N) series. Currently branded Plextor owned by the Taiwanese company Lite-On, which previously manufactured discs for Plextor under contract.

Corsair. The American company is known for the high quality of various products - RAM, power supplies. The company's products are aimed at the so-called "enthusiasts", people who are 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 flash memory production (shared with Toshiba) and some models of this company's SSD drives demonstrate very high performance. The company has a long and successful history of various types of flash drives (USB flash drives, memory cards).

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

Hynix. This Korean company manufactures flash memory. And recently she bought a company that makes LAMD controllers. So now she has SSD drives from her flash memory and with her controller.

SSD drive life

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

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

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

On the basis of this memory, a disk with a capacity of 120 GB was made. The 3000 cycle limit means you can burn your entire disc 3000 times. If you fill it completely every day, then completely clear it and fill it completely again the next day, 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 life span increases to 16 years.

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

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

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

And finally, many disk manufacturers, in the specifications of disks, explicitly indicate disk write limits in gigabytes per day. For example, Samsung in the specifications of the 840 Pro disk writes: "5 years warranty is provided on condition that no more than 40 gigabytes per day are written to the disk.". And Micron, for its Crucial M550 drive, specifies a write limit of 72 terabytes, or about 66 gigabytes per day for three years.

However, in 2015, Samsung gives a 10-year warranty for some models of the PRO series.

In 2017, I can say from my own experience that none of the drives that I installed more than 3 years ago have yet broken. True, I have never installed SmartBuy discs. Only Plextor, SanDisk, Samsung, Toshiba, Intel.

Update 2019.

Firstly, the question of the unreliability of TLC memory can be said to be removed. At least for the market leaders. In 2019, the largest flash memory manufacturers, Intel, Micron, Samsung, declare the write resource for their TLC memory to be the same as that provided for MLC memory a few years ago. And this resource is such that it allows them to give a 5-year warranty on their SSD drives. And such a warranty period is very rare to get on an HDD.

Secondly, from my own experience, I can add that out of several dozen SSDs that I have installed in computers over the past 6 years, only one has failed - the budget Plextor model (S lineup). And this Plextor did not die to the state of a brick - at the very least, but it worked, so it turned out to copy the data from there. For comparison, over the same years I replaced about a dozen HDD drives - due to their failure. Especially often HDD drives die in laptops.

So, today SSD is more reliable than HDD. However, you need to keep in mind that we are talking about SSD drives from the best manufacturers (the first eight). Drives like SmartBuy, Dexp and the like are, I guess, a big lottery.

How to extend the life of an SSD drive

Free disk space. Do not "fill" it completely - try to have 20 - 30 percent free space on the disk. The presence of free space allows the controller to even out the wear of memory cells. This free space must be unallocated, that is, not assigned to any partition with the file system. By the way, the presence of such an unallocated space also allows you not to bother about TRIM.

Uninterrupted power supply. If you are using an SSD in a regular computer, connect the computer via a UPS. If the SSD is in a laptop, monitor the battery status - do not turn off the laptop when the battery is completely discharged. SSD drives don't like sudden power loss. In the event of an abnormal power failure on the disk, data in the flash memory cells may be corrupted. Alternatively, you can buy a drive model that has Power Loss Protection.

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

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

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

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

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

Installing an SSD on an old motherboard

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

If you have an old motherboard that has a SATA 2 (SATA 300) controller, then the new SSD will not run at its full speed. There are two options to fix things:

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

Although, in my opinion, it's easier to leave it as it is. In real life, the difference in speed between a SATA 2 connection and a SATA 3 connection may not be very large. It will manifest itself only in operations with reading large amounts of data located sequentially on the disk. And accordingly, with sequential recording, large amounts of data. In practice, writing and reading usually occur in small volumes in arbitrary (inconsistent) areas of the disk. And in this mode, most of the budget SSD drives give a speed of less than 300 MB per second.

However, an SSD mounted on a PCI-e card is generally a good idea, as it will perform faster than if connected via a SATA 3 controller. But this solution also has a drawback. A disk mounted on a PCI-e board cannot be installed in a laptop, and a simple SATA SSD can be used in any computer - in a regular one, in a laptop, in a monoblock, in a nettop.

Common Mistakes When Using SSD Drives

Error one

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

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

Indeed, the space on the SSD is saved and the life span is increased. But at the same time, the speed of the computer is significantly reduced. After all, the faster the disk reads or writes temporary files, documents, profile files, the faster the work is done.

My categorical opinion is that everything related to the OS and programs should be placed on an SSD drive. Working documents also need to be stored on an SSD drive. It makes sense to store only large volume data on the HDD - music, movies. Or data that is very rarely used - archives. Only then will you get the best speed from your SSD drive. Don't 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 a habit left over from using HDD drives, people defragment an SSD drive as well. You don't need to do this! The speed of access to arbitrary data blocks in an SSD drive is about two orders of magnitude higher compared to an HDD. Therefore, data fragmentation is no longer reflected in the speed of reading this data.

Summary

Basic parameters of SSD drives

• Manufacturer. The best manufacturers of SSD drives are Intel, Micron (Crucial brand), Samsung, Plextor, SanDisk, Toshiba, Corsair.
• Disk capacity. The minimum disk size that gives great speed and a good supply of free space to extend the life is 240/256 gigabytes. Drives with a capacity of 60 - 128 GB, will almost certainly write speeds below 200 MB per second. Although there are separate models of such disks with a write speed of more than 200 MB per second.
• Controller. The best controllers today are Samsung, Marvell, Intel, Silicon Motion. Intel and Samsung controllers are used only in drives from these manufacturers. Marvell and Silicon Motion controllers are used in drives from different manufacturers.

Secondary parameters of SSD disks

• Memory type. SLC memory "lives" the longest, but such memory is not available in retail today. MLC and TLC memory, in descending order, have a shorter lifespan. In 2018, there are already few disks with MLC memory, most disks use TLC memory.
• Memory process technology. Memory crystals created using the 19 or 20 nanometer process technology have a shorter lifespan than crystals created using the 25 nanometer process technology. In 2018, memory is already being produced according to the 14 nanometer process technology.
• Hardware encryption with support for TCG Opal 2.0 and IEEE-1667.
• Power loss protection.

Which SSD drive to choose

Roughly like this:

• Manufacturer: Intel, Samsung, Plextor, Corsair, Micron (Crucial).
• Memory type: NAND Flash MLC or TLC.
• Disk size: ranging from 240 - 256 GB.

For example, these 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 speed to date. A disk Intel S3500 will provide the highest guarantee of data integrity and safety.

Attention! These are older models that have been discontinued. See the update sections at the end of the article for current models.

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

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

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

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

If the SSD is going to be used with an old operating system, such as Windows XP, it makes sense to think about the effect of "speed degradation" and how to avoid it (more in the section).

Data recovery

SSD drives have one disadvantage compared to HDD drives. In the event of a breakdown, recovering data from a "dead" SSD drive will be much more difficult, and most often impossible at all.

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 some cells, especially those where service information is stored, can lead to the impossibility of data recovery.

There is one more feature. Even on a healthy SSD, recovering previously deleted files may not be possible. If TRIM is enabled for the drive, then the controller will shred the deleted file data.

On HDDs, the data of deleted files is not destroyed until space is needed for new files. And this makes it possible to recover deleted files (not always, but often).

So, follow the most important computer rule - Make copies of important data. This rule, however, applies in general to any type of disk, and not just to SSDs. Any disk can die at any moment.

Update 2015

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

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

Prices (dollars) are falling, productivity is rising.

An interesting five 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

The good news is that SSD drives using TLC memory can have a lifespan comparable to MLC drives.

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

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

The Samsung EVO 850 and Plextor M7V drives show very impressive results in memory endurance tests. At the level of good disks with MLC memory.

And the speed is very good too. for instance 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 proprietary Plextool program). But Plextor M7V is a budget model, one of the cheapest among all SSD drives in mid-2016.

A disk Samsung EVO 850(250 GB) gives speeds (measured in Samsung's proprietary program):

• On a SATA 2 controller (Intel ICH9): 268 Mb/s read and 250 Mb/s write. This speed is also confirmed by measurements in Ubuntu Linux.
• On a SATA 3 controller (Intel): 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 read speed also rests on the standard limit. And at the same time, Samsung gives a 5-year warranty on the drives of the line EVO 850. And it turns out extremely fast and very reliable disk.

Update 2017

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

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

Speeds closer to 1 GB per second (or higher) depend on whether both the drive and the motherboard support the NVMe (NVM Express) protocol. This is a protocol for working with disks over the PCI-e bus. It is similar to the AHCI protocol, but has advantages over it. The NVMe protocol emphasizes the parallelization of read and write operations. And it has a large job queue depth.

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

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

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

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

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

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

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

What are the benefits of using an NVMe-enabled SSD? At a minimum, today, this is about twice the speed of operation compared to 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, it makes sense to bother.

If you are buying a new computer in 2017, then I advise you to take a motherboard and an NVMe-enabled SSD.

Update 2018

Cheap models

A lot of SSDs have appeared on sale with the most cheap hardware platform. Manufacturers reduce the number of processor cores, the number of memory channels, remove the DRAM cache (the so-called DRAM-less controllers). For example, the Phison S11 controller is not only single-core, but also dual-channel and without a DRAM cache. Such disks have a low price and beautiful numbers in terms of read and write speed, in the specifications

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

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

Some of these models:

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

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

SATA is fading into history

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

So if you're looking to buy a new computer or upgrade, look for an M.2 motherboard with NVMe support. And put an M.2 NVMe SSD in there. However, please note that an M.2 motherboard or an M.2 drive may not support the NVMe protocol - in this case, the drive will operate at SATA3 speed (SATA mode). It is necessary to clarify whether a specific motherboard and a specific M.2 SSD drive has NVMe support.

3D XPoint (Intel Optane memory)

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

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

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

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

Good and inexpensive SSD drives

SATA Samsung 850MZ-7LN120BW- just 850 without the EVO suffix. So far, there is only one model in the line, for 120 GB. It costs around 3500 rubles (summer 2018). In this model, everything is grown-up - DRAM cache, a good controller, plus a new 64-layer TLC 3D V-NAND memory. As a result, very good speed indicators. A good resource for recording is 75 Terabytes.

SATA Hynix SL308- in the line of models for 120, 250 and 500 GB. DRAM cache, own controller, own memory, aluminum housing. Like Toshiba, Intel and Samsung, Hynix also manufactures SSD drives from its own components. A 120 GB model costs around 3,500 rubles.

SATA Crucial MX500- almost a twin brother of the disk Intel SSD 545s. The differences are that it uses a dynamically changing pseudo-SLC cache and there are capacitors to protect against sudden power loss (so that the write operation can be completed).

SATA Crucial Micron 1100- the minimum volume in this model line is 256 GB. There is such a model in the region of 6500 rubles. It uses a Marvell controller, DRAM cache and its own TLC 3D NAND memory.

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

Update 2019

The good news is that good quality TLC memory has appeared, with a large write resource. And SSD drives with TLC memory, on average, give higher write and read speeds than drives with MLC memory. Moreover, they are also cheaper. A good 250 GB SATA SSD can now be purchased for $50-60.

So, now, in the budget segment, there are models that are more productive and more capacious than they were in the premium segment a few years ago.

The bad news is that the number of frankly deshmanic SSD drives has increased. Which are of course very cheap, but buying them is very risky. The number of "manufacturers" of SSD drives is increasing every year. And in these mountains of shit it is not easy to find a good product.

Best SATA SSD Options for February 2019:

• SATA Intel SSD 545s- 256 GB.
• SATA Samsung 860 EVO MZ-76E250BW- 250 GB.

Top M.2 SSD options for March 2019:

• M.2 NVMe Intel 760p- 256 GB.
• M.2 NVMe Samsung 960 EVO- 250 GB.

Cheap, capacious, fast drives. Read more about these models in the 2018 section.

Ivan Sukhov, 2014, 2015, 2016, 2017, 2018, 2019 .

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If you are building a powerful computer or want to speed up an old one, then an SSD will come in handy. Finally, the cost of these drives has dropped enough that they can be considered as a reasonable alternative to hard disk drives (HDDs).

The SSD features listed below will help you choose the best drive that is compatible with your computer and meets your needs.

1. Which form factor to choose: SSD 2.5″, SSD M.2 or other

SSD 2.5″

This form factor is the most common. An SSD looks like a small box that resembles an ordinary hard drive. 2.5″ SSDs are the cheapest, but at the same time, their speed is enough for most users.

Compatibility SSD 2.5″ with computers

An SSD of this form factor can be installed in any desktop or laptop computer that has an open bay for 2.5-inch drives. If your system only has room for an old 3.5″ hard drive, you can put a 2.5″ SSD in that as well. But in this case, look for an SSD model that comes with a special lock.

Like modern HDDs, a 2.5″ SSD is connected to the motherboard using the SATA3 interface. This connection provides throughput up to 600 MB/s. If you have an older motherboard with a SATA2 connector, you can still connect a 2.5″ SSD, but the drive's bandwidth will be limited by the old version of the interface.

SSD M.2

A more compact form factor, due to which it is suitable even for especially thin ones, in which there is no place for a 2.5 ″ SSD. It looks like an oblong stick, it is installed not in a separate compartment of the case, but directly on the motherboard.

Each M.2 drive uses one of two interfaces to connect to the board: SATA3 or PCIe.

PCIe is several times faster than SATA3. If you choose the first one, then there are a few more things to consider: the version of the interface and the number of data lines connected to the connector.

• The newer the PCIe version, the higher the bandwidth (data transfer rate) of the interface. Two versions are common: PCIe 2.0 (up to 1.6 GB / s) and PCIe 3.0 (up to 3.2 GB / s).
• The more data lines connected to the SSD connector, the higher its bandwidth again. The maximum number of lines in an M.2 SSD is four, in this case, in the description of the drive, its interface is designated as PCIe x4. If there are only two lines, then - PCIe x2.

M.2 SSD Compatibility with Computers

Before buying an M.2 SSD, you need to make sure it will fit your motherboard. To do this, first check the physical, and then the software compatibility of the connector on the drive with the slot on the board. Then you need to find out the length of the drive and compare it with the allowable length of the slot allocated for M.2 in your system.

1. Physical compatibility of interfaces

Each connector on the motherboard, designed to connect M.2 format drives, has a special cutout (key) of one of two types: B or M. At the same time, the connector on each M.2 drive has two B + M cutouts at once, less often only one of two keys: B or M.

You can connect to the B-connector on the board with a B-connector. To the M-connector, respectively, a drive with an M connector. SSDs, the connectors of which have two M + B cutouts, are compatible with any M.2 slots, regardless of the keys in the latter.

M.2 SSD B + M key (upper) and M.2 SSD key M (lower) / www.wdc.com

So first make sure your motherboard has an M.2 SSD slot at all. Then find out the key of your connector and select a drive whose connector is compatible with this key. Key types are usually indicated on connectors and slots. In addition, you can find all the necessary information in the documents for the motherboard and drive.

2. Logical compatibility of interfaces

In order for an SSD to fit your motherboard, taking into account the physical compatibility of its connector with the connector is not enough. The fact is that the drive connector may not support the logical interface (protocol) that is used in the slot of your board.

Therefore, when you figure out the keys, find out which protocol is implemented in the M.2 connector on your board. It can be SATA3 and/or PCIe x2 and/or PCIe x4. Then choose an M.2 SSD with the same interface. See the device documentation for information about supported protocols.

3. Size compatibility

Another nuance that determines the compatibility of the drive with the motherboard is its length.

In the characteristics of most boards, you can find the numbers 2260, 2280 and 22110. The first two digits in each of them indicate the supported drive width. It is the same for all M.2 SSDs and is 22 mm. The next two digits are the length. Thus, most boards are compatible with drives with a length of 60, 80 and 110 mm.

Three M.2 SSD drives of different lengths / www.forbes.com

Before purchasing an M.2, be sure to check the supported length of the drive, which is listed in the documentation for the motherboard. Then choose the one that matches that length.

As you can see, the issue of M.2 compatibility is very confusing. Therefore, just in case, consult on this matter with the sellers.

Less popular form factors

Your computer case may not have a 2.5” SSD bay, and your motherboard may not have an M.2 slot. The owner of a thin laptop may encounter such an atypical situation. Then for your system you need to choose a 1.8 ″ or mSATA SSD - check in the documents for your computer. These are rare form factors that are more compact than 2.5 ”SSDs, but are inferior in data transfer speed to M.2 drives.

In addition, thin laptops from Apple may not support traditional form factors either. In them, the manufacturer installs a proprietary SSD format, the characteristics of which are comparable to M.2. So, if you have a thin laptop with an apple on the lid, check the supported type of SSD in the documentation for the computer.

External SSDs

In addition to internal, there are also external drives. They vary greatly in shape and size - choose the one that will be more convenient for you.

As for the interface, they connect to computers via a USB port. For full compatibility, make sure the port on your computer and the drive connector support the same USB standard. USB 3 and USB Type-C specifications provide the highest data transfer speed.

2. Which memory is better: MLC or TLC

According to the number of bits of information that can be stored in one cell of flash memory, the latter is divided into three types: SLC (one bit), MLC (two bits) and TLC (three bits). The first type is relevant for servers, the other two are widely used in consumer drives, so you have to choose from them.

MLC memory is faster and more durable, but more expensive. TLC is correspondingly slower and endures fewer write cycles, although the average user is unlikely to notice the difference.

TLC memory is cheaper. Choose it if economy is more important for you than speed.

The type of mutual arrangement of memory cells can also be indicated in the description of the drive: NAND or 3D V-NAND (or simply V-NAND). The first type implies that the cells are arranged in one layer, the second - in several layers, which allows you to create high-capacity SSDs. According to the developers, the reliability and performance of 3D V-NAND flash memory is higher than that of NAND.

3. Which SSD is faster

In addition to the type of memory, other characteristics, such as the model of the controller installed in the drive and its firmware, also affect the performance of the SSD. But these details are often not even indicated in the description. Instead, they feature final read and write speed indicators, which are easier for the buyer to navigate. So, when choosing between two SSDs, other things being equal, take the drive whose declared speeds are higher.

Remember that the manufacturer indicates only theoretically possible speeds. In practice, they are always lower than stated.

4. How much storage is right for you

Of course, one of the most important characteristics when choosing a drive is its volume. If you're buying an SSD to turn it into a fast operating system, a 64GB device is enough. If you are going to install games on the SSD or store large files on it, then choose the amount that suits your needs.

But do not forget that the capacity of the drive greatly affects its cost.

Buyer's checklist

• If you need a drive for office tasks or watching movies, choose a 2.5″ or M.2 SSD with SATA3 interface and TLC memory. Even such a budget SSD will work much faster than a regular hard drive.
• If you're doing other tasks where high storage performance is critical, choose an M.2 SSD with PCIe 3.0 x4 interface and MLC memory.
• Before buying, carefully check the compatibility of the drive with your computer. If in doubt, consult the sellers on this issue.

Greetings dear friends! When choosing an SSD drive for a computer (you can learn more about this), you will find various types of memory in the characteristics. There are not so many of them, but they still differ in parameters.

Today we’ll talk about what type of memory is best for an SSD and what you should pay attention to first. Shall we start?

Existing Options

Almost every solid state drive today runs on NAND memory. Depending on the features, they are divided into three types:

• SLC - single-level. Each cell remembers one bit depending on the state - it can be turned on or off. It has the lowest power consumption, the highest rewriting speed and the number of its cycles. However, it is expensive, so it is used mainly in cool server solutions.
• MLC - multi-level. The cell remembers two bits. It costs less, as the characteristics are "simpler". Used primarily on workstations and mid-range servers.
• TLC - three-level. The cell remembers three bits. It has the highest density, is less hardy and works relatively slower. The most affordable type, therefore, it is widely used in solid-state drives designed for mass consumption.

These types are of the planar type, meaning they are "flat". Their common drawback is that in order to increase the density, it is necessary to reduce the technical process, and it is impossible to do this indefinitely for physical reasons.

3D cells are free of these shortcomings. Cylinder shaped. They are called 3D V-NAND or 3D TLC. Specifications correspond to the planar type of TLC memory.

Manufacturers

There are fewer companies that make chips for solid state drives than there are brands that make SSD drives.
In 2017, production was carried out by:

• Intel/Micron;
• Toshiba/SanDisk
• Hynix;
• Samsung.

It is no coincidence that the first two paragraphs contain two companies through a slash - these brands have established joint production and label products in approximately equal proportions.

All brands that produce SSDs buy chips from these companies, so essentially the same storage devices are installed on different brands. There are no fundamental differences between memory brands: they are produced according to a single technological process and cost approximately the same.

The price is already affected by transportation costs: in 2018, buying a drive with memory made in Singapore will cost less than with memory made in the USA, given that the cost of chips and controllers is also approximately the same.

Which one to prefer

Having studied any performance table, it is easy to make a choice:

• TLC or MLC - the latter is more reliable and faster;
• MLC or 3D NAND - the latter is slower and designed for fewer rewrite cycles;
• TLC or MLC 3D V-NAND - as mentioned above, single-level memory is better in terms of technical parameters.

Since solid state drives are bought primarily for the sake of increasing computer performance, faster loading of the operating system and games, it is logical that it is preferable to use single-level memory. However, everything depends on the price: as I noted, such a pleasure will be very expensive.
Is it rational to overpay if you upgrade or collect, albeit fancy, but still an ordinary home computer? Definitely not.

Therefore, TLC is exactly the kind of cells that you should focus on when choosing a solid state drive. By the way, in this case, the publication "" will be useful to you. Although this memory is slow compared to other types, it is significantly faster than a conventional hard drive.

About hard drive manufacturers and which brand to prefer, you can.

And as a possible purchase, I can recommend the device Kingston SSDNow A400 240GB 2.5″ SATAIII TLC (SA400S37/240G), which has very good parameters at an affordable price, and you can buy it in this popular online store.

Thank you for your attention and see you in the next posts. Share this article with your friends on social networks and don't forget to subscribe to the newsletter!

Good afternoon, dear readers, today we will analyze how much free space do you need on the ssd to install the Windows operating system, how to predict further data growth so that everything works like clockwork and does not disable the device.

SSD(Solid state drive) is a drive in which there are no moving parts, such as in a conventional hard drive. Flash memory is used to store memory in an SSD. In simple words, this is such a big flash drive that has become very firmly established in our lives.

Why you need an ssd drive

And so we figured out the definition, now let me answer the question of what an ssd is for and where it is used. Literally 5 years ago, all computers and server solutions had HDD hard drives as a disk subsystem, which already ran into their performance due to their design and spindle speed. The world demanded further development, especially in the field of mobile devices, it was they who became the locomotive that pushed the new technology, Solid state drive. SSD drives brought us:

• hundreds of thousands of input / output operations (IOPS) compared to HDDs that delivered a maximum of 150 iops,
• reduced electricity consumption,
• reduced the amount of physical space required inside servers and computers

• Stopped warming up
• They became more durable and are not critical to falling or lightly hitting them
• Reduced device weight
• Laptops get extended battery life

I think you now understand why you need an ssd drive to make your life more comfortable and less nervous. How many times have I seen people at work whose hard drives began to die, after checking their condition with a special utility, I stated that the disk would soon be destroyed, there was nothing to change for, be patient. And now a man with gnashing of teeth and wild brakes of the operating system, tried to work, getting irritated every minute, more and more. With ssd, this does not threaten, it only has a 5-year warranty period from the manufacturer, and with average use in companies, it will live all 8-10 years, saving a lot of money to employers.

SSD volume in 2017-18

And so we figured out the question of why we need an ssd drive, now let's talk about its volume, which the modern user is most interested in. When above I told you about the comparison of hdd and ssd, about all its advantages, I forgot to mention two significant disadvantages that are still holding back its mass exclusion from the market of servers and personal computers:

1. Much smaller volume compared to HDD
2. The price can be several times higher than that of hard drives

Although the volume of SSDs increases and the price per gigabyte decreases every year, they still leave much to be desired, HDDs still win by the volume and price per gigabyte formula. In such situations, they come to a compromise, in which a solid-state drive (SSD) is used for a clean installation of Windows 7 and higher, and a regular HDD 3.5 is used for any data.

At the moment, the largest ssd is 15 TB and costs $ 10,000, which only large companies can afford, for very fast RAID arrays. Here's what this solid state drive looks like, from Samsung.

But this, as it turns out, is not the limit, Samsung is already developing an SSD with a capacity of 60 TB and this is already a very serious volume, I think that in the next 5-7 years this market will grow strongly and make the price of SSDs lower than that of hard drives.

How much ssd is needed for windows 10

Let's now figure out how big a solid state drive should be that has Windows 10 Creators Update installed on it. Here I can give figures from my practice, which includes servicing more than 700 computers with this OS.

• For Windows 10 itself, you will need a 20 GB ssd drive
• At the time of installing the updates, the Windows 10 operating system may require an additional 15 GB from you, just an example of the transition from threshold 2 to anniversary update , at this moment the Windows.old folder is created so that the user can roll back the system at any time.
• Third party programs from 10 GB
• Space for temporary files, about 5-10 GB

I summarize for Windows 10, you will need a ssd solid-state drive in the amount of 120 GB, at current prices, it will cost you from 3200 rubles, which is not very expensive, the only thing you have to do is to tune it to reduce its wear and tear and buy an additional screw for your main files (Music, photo, video)

How much ssd is needed for windows 7 and 8.1

Let's now figure out how big a solid-state drive should be, which has Windows 7 or 8.1 on it.

• The seven itself will require from 12-15 GB, but with constant updates, the folder can grow up to 30 GB, so you will have to constantly clean up old updates.
• The Microsoft Office suite will require another 5-7 GB of space from you
• Third party programs from 10 GB

I summarize, the seven will fit into 60 GB, but I advise you not to be asshole and buy 120 GB. The most joyful thing is that this technology only improves every year, we will wait. Today we looked at what an ssd drive is and why you need it, if you have questions, then write them in the comments, I will try to answer.

Currently, solid state drives or SSDs are gaining more and more popularity ( S solid S tate D river). This is due to the fact that they are able to provide both high file read-write speed and good reliability. Unlike conventional hard drives, there are no moving parts, and a special NAND flash memory is used to store data.

At the time of this writing, SSDs use three types of flash memory: MLC, SLC and TLC, and in this article we will try to figure out which one is better and what is the difference between them.

NAND flash memory was named after a special kind of data markup - Not AND (logical NOT AND). Without going into technical details, let's say that NAND organizes data into small blocks (or pages) and allows you to achieve high data reading speeds.

Now let's look at what types of memory are used in solid state drives.

Single Level Cell (SLC)

SLC is an outdated type of memory that used single-level memory cells to store information (by the way, the literal translation into Russian sounds like “Single-level cell”). That is, one cell stored one bit of data. Such an organization of data storage made it possible to provide high speed and a huge rewriting resource. So, the read speed reaches 25 ms, and the number of rewrite cycles is 100,000. However, despite its simplicity, SLC is a very expensive type of memory.

Pros:

• High read-write speed;
• Great rewrite resource.

Minuses:

• High price.

Multi Level Cell (MLC)

The next stage in the development of flash memory is the MLC type (translated into Russian it sounds like a “multi-level cell”). Unlike SLC, two-level cells are used here, which store two data bits each. The read-write speed remains at a high level, but the endurance is significantly reduced. Speaking in the language of numbers, here the read speed is 25 ms, and the number of rewrite cycles is 3,000. This type is also cheaper, which is why it is used in most solid state drives.

Pros:

• lower cost;
• High read-write speed compared to conventional disks.

Minuses:

• Low number of write cycles.

Three Level Cell (TLC)

And finally, the third type of memory is TLC (the Russian version of the name of this type of memory sounds like a “three-level cell”). Relative to the previous two, this type is cheaper and is currently found quite often in budget drives.

This type is denser, with 3 bits stored in each cell. In turn, high density leads to a decrease in read / write speed and reduces the endurance of the disk. Unlike other types of memory, the speed here has dropped to 75 ms, and the number of rewrite cycles to 1,000.

Pros:

• High storage density;
• Low cost.

Minuses:

• Low number of rewrite cycles;
• Low read-write speed.

Conclusion

Summing up, it can be noted that the fastest and most durable type of flash memory is SLC. However, due to the high price, this memory was supplanted by cheaper types.

Budget, and at the same time, less high-speed is the TLC type.

Finally, the golden mean is the MLC type, which provides higher speed and reliability than conventional drives, and is not too expensive. For a better comparison, see the table below. Here are collected the main parameters of the types of memory for which the comparison was made.