Ssd disk for a computer which is better to buy. The lifespan of the SSD. NAND flash cell types

More and more users are purchasing SSD drives for installation in PCs. They are used in parallel with the HDD or instead of them. Solid state drives have many advantages over hard drives. Therefore, you need to know how to choose the right SSD drive for your computer.

What is it?

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

Advantages and disadvantages

Benefits:

• high speed of data read / write and work performance;
• low heat generation and power consumption;
• no noise due to the absence of moving parts;
• small dimensions;
• high resistance to mechanical damage (overload up to 1500g), magnetic fields, temperature extremes;
• stability of data reading time regardless of memory fragmentation.

Disadvantages:

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

Main characteristics

If you are buying an SSD to install on 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 only purchase it to install the OS, select a device with 60GB or more memory.

Today's 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 storage capacity of 120 GB or more.

If you are purchasing a solid state drive instead of a hard drive, consider how much information is stored on your computer. But in this case, the capacity of the SSD disk should not be less than 250 GB.

Important! The cost of a solid state drive directly depends on the volume. So if your budget is tight, use an SSD to install the operating system and HDD to store your data.

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

Good to know! To install a 2.5 "SSD drive into a standard 3.5" mount inside the PC case, special adapters are used. Some chassis models have 2.5-inch slots.

There are 1.8-inch and smaller SSDs on the market that are used in compact devices.

Connection interface

Solid state drives have several connection interfaces:

• SATA II;
• SATA III;
• PCIe;
• mSATA;
• PCIe + M.2.

The most common option is to connect using a SATA connector. There are still SATA II models on the market. They are no longer relevant, but even if you purchase such a device, due to the backward compatibility of the SATA interface, it will work with a motherboard that supports SATA III.

If you are using a PCIe SSD, you may need to install drivers, but the transfer speed will be faster compared to a SATA connection.

MSATA models are used on compact devices, but work in the same way as the standard SATA interface.

The M.2 or NGFF (Next Generation Form Factor) models are a continuation of the development of the mSATA line. They are smaller and more flexible for digital manufacturers.

Read / write speed

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

• read 450-550 Mb / s;
• write 350-550 Mb / s.

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

Also, pay attention to the access times. This is the time it takes for the disk to find the information required by the program or OS. The standard rate is 10-19 ms. But since SSDs have no moving parts, they are significantly faster than hard drives.

Memory type and runtime

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 two bits of information to be stored in one cell. It has a relatively small resource of rewriting cycles (3,000 - 5,000), but a lower 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 one cell. These microcircuits are distinguished by a long life time (up to 100,000 rewriting cycles), high data transfer rates, and minimal access times. But due to the high cost and small amounts of data storage, they are used for server and industrial solutions.

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

Helpful! Recently, manufacturers have managed to increase the lifetime of TLC disks up to 3,000 rewriting cycles.

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

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

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

TRIM function

The most important additional feature for an SSD is TRIM (garbage collection). It is as follows.

Information on the SSD is first written to free cells. If the disk writes data to a cell that was previously used, it first clears it (unlike HDD, where data is written over the existing information). If the model does not support TRIM, it clears the cell just before writing new information, which causes the speed of this operation to drop.

If the solid-state drive supports TRIM, it receives a command from the OS to delete the data in the cell and clears it not before overwriting, but during the "idle" of the disk. This is done in the background. This maintains the write speed at the manufacturer's specified level.

Important! The operating system must support the TRIM function.

Hidden area

This area is not accessible to the user and is used to replace failed cells. In high-quality solid state drives, it is up to 30% of the device volume. But some manufacturers, in order to reduce the cost of an SSD drive, reduce it to 10%, thereby increasing the amount of storage available to the user.

The flip side of this trick is that the hidden area is used by the TRIM function. If its volume is small, it will not be enough for background data transfer, which is why the write speed will drop sharply at the SSD "load" level of 80-90%.

Model overview

Below is a list of several popular models.

SSD drives are becoming more and more popular today and an increasing number of users have a desire to install this productive device on their laptop or desktop PC. Fortunately, recently the prices for such devices have seriously decreased, but still SSD remains quite expensive in comparison with HDD. However, if high performance is important to you and you are not afraid of the cost, then believe me, this device will not disappoint you. In this article, we will tell you how to choose an SSD drive for a laptop, what parameters and technical characteristics you should initially pay attention to.

Benefits of buying

Buying an SSD for your computer is one of the most important steps to improve system performance and data processing speed. On such a device, access to information is much faster.

Important! Replacing an outdated HDD with a more modern device will bring more power gains than even adding more memory or installing a new processor.

The advantages of a laptop SSD include the following:

• Increasing the speed of accessing data, which will significantly speed up the launch of programs. Before you get puzzled about changing the configuration of your PC, it makes sense to take preventive measures. They will take you a while, but they can be very effective. Find out, .
• The small size of most devices (except for portable models), allowing you to easily select an SSD for a small 10-inch netbook, and for a large laptop with a 17-inch display.
• Low weight, which is especially important when used on a laptop.
• Reduced power consumption, which should increase the average laptop battery life.
• High level of SSD reliability.

Important! Among the disadvantages that can be noted in solid-state drives, attention is paid to their rather small resource: approximately 3000-5000 cycles. For typical home use, this is equivalent to approximately 8 years of work.

Volume

Before choosing an SSD drive for a laptop, you need to decide how much volume you need. As a rule, an SSD is used as a system disk for installing an operating system:

• Determine how much space your OS is currently occupying. Consider how much space you will need for related programs. If you are a fan of playing games, then this is also worth considering.

Important! It is already difficult to find SSDs up to 60 GB in stores. The minimum cost for such a disk will be about the same as for a 1 TB HDD.

• In principle, if you do not plan to install a large number of different programs, a 60 GB SSD will be enough for you to use it as a system one. However, if funds allow, then it is better to pay attention to disks with a volume of 128 GB or more.
• It is worth remembering that some SSDs degrade their performance when they are over 70% full. That is why the disc should be taken with a margin.
• Also pay attention to the peculiarity of such devices, which is that high-power SSDs have a high data transfer rate. Especially with regards to the recording.
• The difference in speed between a 128GB drive and a 512GB drive of the same model can be up to three times. This difference is due to the fact that the SSD controller uses all the memory crystals at the same time. One model uses the same memory dies, so less capacity means fewer dies, and fewer dies means less speed.

Important! Don't confuse memory crystals with memory chips. Each of the microcircuits can contain several crystals. That is, drives of different capacities can have the same number of microcircuits, while the number of crystals will be different.

Manufacturers indicate this transfer rate difference in the specifications of the drive models. Therefore, before buying a disc, carefully study its specification - perhaps a disc of suitable size will not be as fast as you need.

Important! And the speed of any PC depends on the efficiency of the cooling system. Therefore, be sure to read about:

Interface

When asked which SSD to choose for a laptop, it is worth paying considerable attention to the interface.

SATA

Today, all SSDs are available with a SATA 3 interface. If suddenly you come across drives with a SATA2 interface, then buying such devices is no longer worth it. But many users still have many PCs in their hands with motherboards with a SATA 2 or even SATA 1 controller installed.

You can safely install a drive with a SATA 3 interface on such devices, you just need to take into account that in this case, the real speed will be significantly lower than the declared characteristics.

Important! This problem can be solved by purchasing a separate SATA 3 controller and connecting it to the motherboard. In any case, a device with SATA 3 interfaces will be the best choice.

PCI-Express

Now models of drives made in the form of PCI-express cards have begun to appear, for example, PlextorM6e. In this case, you simply install the drive card into the PCI-e slot, and then enjoy the work of the disk.

Memory type

There are three types of memory that are used to create solid state drives:

• SLC is a kind of memory, each of the physical cells of which stores 1 bit of data. Its advantage is its durability and higher working speed. The disadvantage is the high cost.

Important! The old type is extremely rare on sale.

• MLC is a type of memory, in each of the physical cells of which 2 bits of data are stored. Such cells can be in different states of charge, which increases the volume.

Important! The disadvantage of this type of memory is that it has longer access times and reduced service life compared to SLC memory. The operating time of such a drive is on average no more than 3 years, but at the same time they are cheaper. This is the most popular type of memory.

• TLC is a kind of memory, in each of the physical cells of which 3 bits of data are stored. It is the newest type of memory.

Important! Since SLC-based drives are small in capacity and high in price, MLC drives are mostly sold. Devices with TLC memory have just started to appear on the market.

Taking into account the fact that drives based on MLC memory are a more reliable and proven option, when buying, you should give preference to this particular type of memory.

Important! When you are going to improve the device of your computer, take care of its internal cleanliness. To do this, select from our review.

Controller

The main part of the SSD is the controller. It is on him that the reliability, quality and speed of the drive depend, so when choosing an SSD drive for a laptop, you should pay attention to this parameter. There are several types of controllers on the modern market:

• SandForce is the most popular type of controller and one of the fastest. They dominate the budget SSD category. Even Intel makes some SSDs based on controller data. Its job is the principle of data compression, which is performed before writing to disk. All this makes it possible to increase performance and reduce memory access time. Compressed data takes up less space, which reduces the number of cell accesses, which increases the disk life.

Important! These controllers have some not very pleasant feature - after filling the drive and then cleaning it, the write speed is not restored to its original values. It also slows down if the drive is too full. At the same time, SandForce has an excellent write speed of highly compressible information.

• Intel - these controllers, due to their reliability, are often used in workstations and servers. Intel's not-so-high write speed prevents Intel from becoming the market leader.
• Marvell is a widely used controller. Models of this company 88SS9174 and 88SS9187 are used in high-performance SSDs from different companies. For example, some of the world's fastest SSDs, the PlextorM5, CrucialM550 use these controllers.

Important! It is considered one of the fastest and cheapest in the world. The speed is not much faster than SandForce, but it can work with it on an equal footing.

• Phison - this manufacturer has long been known for its controllers for flash drives. More recently, it has begun to conquer the SSD market. Its drives are used in budget models.
• MDX - Created by Samsung and used in its drives. It has good speed results, which makes it a worthy competitor in the SSD market.
• Indilinx is a controller that shows very good read and write speeds. Perfectly optimized for SSD performance. Currently, the company of the same name belongs to OCZ, so all drives from this company are manufactured on the basis of this controller.

Important! Each of the presented controllers has its own characteristics - strengths and weaknesses. When choosing an ssd drive for a laptop, you should pay attention to SandForc, Intel, Indilinx, Marvell.

Manufacturers

There are many SSD manufacturers on the PC device market today, but among the variety, there are five major manufacturers that have captured most of the market and are building decent solid state drives. Basically, you can buy a disc from any of these companies:

• Intel - manufactures disks from their memory and selects the best memory for their SSDs. And some of these drives are also assembled by the manufacturer on the basis of their own controllers. The drives of this company are very reliable and of high quality, but quite expensive. Mostly used on servers.
• Crucial (a division of Micron) - together with Intel, produces flash memory. So, the company makes disks based on its memory. It differs from Intel in that it is aimed at a more budget segment. Crucial uses its memory and Marvell controllers.
• Plextor is a Japanese company that doesn't actually make the discs itself - they are assembled for them by a firm called Lite-on. At the same time, the disks are very good. They use Marvell controllers and Intel-Micron memory. The PlextorM5 Pro disk is considered one of the fastest today, even though it is not young at all.
• Samsung is a leader in the SSD market. The firm itself collects both controllers and memory. Therefore, the disks are 100% their own.
• Sandisk - some drive models from this manufacturer show very good performance.

Video

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

Why you need to use SSD drives

Advantages of SSD drives over old HDDs:

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

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

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

How to Pick a Good SSD

Now let's move on to the topic of the article. When choosing an SSD, you need to look at two main characteristics - speed and reliability. The speed depends on the components (memory and controller) that are used in the disk. And reliability from components (such as memory) and manufacturer. Further, in this article all primary and secondary characteristics of electronic disks will be discussed in detail.

SSD drive specifications

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

Manufacturer

Many companies make SSD drives. 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 produces flash memory. Thus, he makes his disks from his own memory and selects the best copies of memory for his disks. It is no coincidence that it gives a 5-year warranty on its drives.
• Micron (trademark Crucial). The company together with Intel releases flash memory. Thus, he makes his disks from his own memory and selects the best copies of memory for his disks. The difference from Intel is that Micron (Crucial) is targeting the budget segment of the market. Lower price, less warranty. But the discs are good.
• 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 - both memory and controllers, all their own.
• Plextor... A Japanese company famous for its laser drives. In fact, the SSD does not make itself - Lite-On makes them for it. But the discs are very good.
• Corsair... The American company is known for the high quality of various products - random access memory, 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.
• Sandisk... American company, one of the leaders in the production of flash drives and SSD drives. Toshiba's partner in flash memory chips. Thus, the disks are made from their flash memory.
• Toshiba... A Japanese company, among other things, a manufacturer of flash memory chips. Thus, the disks are made from their flash memory.

SSD disk capacity

SSD manufacturers indicate this difference in the specifications of their drive models. Therefore, before buying a fast disc - carefully read its specifications, maybe the size you are looking at is not as fast as you expect.

When size matters.

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

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

Some of the manufacturers may not be quite sure about the quality and lifespan of the flash memory used in their model and therefore makes such a reserve. Someone makes such a margin just for greater reliability. For example, in Intel disks, the quality of flash memory is very high, nevertheless, the company reinsures itself by making a reserve of cells.

The controller used in the disk

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

Write speed degradation (garbage collection)

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

SSD secondary characteristics

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

Power loss protection... Some SSD models are protected against sudden power outages. Usually these are just capacitors, the charge of which is enough for the disk to complete the necessary writes to memory cells.

Interfaces

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

SATA

Today (2016) all SSD drives are produced with SATA 3 interface. However, there are still many computers in which motherboards have SATA 2 (SATA 300) and even SATA 1 (SATA 150) controllers. Can a new SSD drive be installed in such a computer?

Sure you may. However, you need to understand that in this case, the new SSD drive will deliver real speed significantly lower than its passport characteristics.

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

But for 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 into your old computer, it will run slower than it can.

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

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

PCI-express

In addition, now there are models of SSD drives 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 plug 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 M.2 to PCI-e adapter card.

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 card and then put an SSD disk with an M.2 interface there. The above disc 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 rate 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 SSD drives in the M.2 form factor, 2 PCI-express lanes are used so that theoretically the exchange rate with the drive can reach 2 GB per second.

Memory

There are two types of 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 handled individually. NAND memory has a longer access time to memory cells, but is significantly cheaper to manufacture.

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

NAND Flash Manufacturers

Memory for SSD drives is made 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 case and subsequent access from the controller, NAND flash can be divided into two types:

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

NAND flash cell types

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

• 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 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 MLC memory is cheaper than the same 128 GB, but SLC type. And 128GB TLC memory is cheaper than the same amount of MLC.

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

That is, with an increase in the number of bits per cell, the lifetime of this cell decreases.

Basic parameters of flash memory for SSD

The main characteristics of flash memory for SSD drives are:

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

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

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

That is, MLC memory will have a shorter lifetime than SLC memory. A memory manufactured using the 25 nanometer process technology will have a lifespan longer than that manufactured using the 19 nanometer process technology.

Memory capacity (size)

Indicated in gigabytes. The peculiarity of SSDs is that larger disks provide faster data exchange rates, especially when writing. The difference in write speed between 120/128 GB and 480/512 GB discs can go up to two or three times.

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

There is no need to confuse memory crystals and memory chips. One microcircuit can contain from one to four memory crystals. 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 manufacturers indicate this write speed difference in the specifications of their drive models. Therefore, before buying a fast disc - carefully read its specifications, maybe the size you are looking at is not as fast as you expect.

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

This difference grows as new 128-bit memory dies are released on the market, instead of 64-bit ones. To put it simply, if an SSD is built on 64-bit memory chips, then the full speed of read / write operations is possible on 240/256 GB disks. 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 disk Crucial M500 built 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.
• 480GB and 960GB - 400 MB per second write speed.

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

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

All SSD controllers use cell interleaving when writing to even out cell wear. Free memory is used for interleaving. Accordingly, the less the disk is occupied by data and programs, the more possibilities the controller has for interleaving cells and the longer the memory will live.

Large disk capacity is the easiest way to increase free disk space. Suppose you have 100 gigabytes of programs and data. If this is placed on a 120 or 128 GB disk, then the disk will be almost completely occupied and there will be few cells 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 a longer and more even wear.

Controllers

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

• SandForce... Now this company is owned by another company - LSI. SandForce controllers such as the SF2881 are the most common. They dominate the budget SSD segment. Even Intel (models 520, 530) produces SSD disks on these controllers.
• Marvell - their controllers 88SS9187 and 88SS9174 are used in high-performance SSD disks from various manufacturers, in particular Micron (Crucial), Plextor, SanDisk. For example, some of the world's fastest SSD drives are Plextor M5 Pro, Crucial M500, Crucial M550use controllers Marvell88SS9187, 88SS9189.
• Indilinx... Now this company is owned by OCZ and the latest controller model is called Barefoot 3. Accordingly, these controllers are used mainly in OCZ drives.
• LAMD (Link_A_Media Devices). Fast but rarely used LM87800 controller. For example used in Corsair Neutron drive models. The company was bought by the Korean Hynix and these controllers are used only in tandem with the Hynix flash memory.
• Phison... This company has long been known for its controllers for USB sticks. Recently, it has launched an offensive 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 developed by Samsung and is used in its drives.
• Intel... Intel uses its own controller in some of its SSD models. These are server models S3500, S3700, as well as the Intel 730 model oriented to the business segment of the market.
• Silicon motion... Another company offering budget SSD controllers. Nothing outstanding in terms of performance.

Different characteristics of an SSD drive depend on the controller. Speed \u200b\u200bof operation, lifespan of flash memory, resistance to data corruption.

For example, Marvell controllers give high performance with operations on arbitrary blocks of data. Just such a load falls on the disks in real computer operation. The Intel controller is focused on high performance in a high concurrent request environment (server load model).

And SandForce controllers have an unpleasant feature - after filling the disk and cleaning it, the write speed does not return to its original values \u200b\u200b(when the disks were empty). It also slows down when the disk is very full. At the same time, SandForce controllers provide high write speed 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 for the last couple of years, Silicon Motion and Phison have been actively working in this segment.

The reason for this is because these companies offer complete solutions for making SSD drives. Not only the controller, but also the firmware for it, as well as the design of the board for mounting all the filling.

Thus, the manufacturer of ready-made disks does not need to do anything other than soldering the parts to the board and mounting the board into the case.

TRIM (garbage collection)

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

When using flash memory, blocks that previously contained some information must be cleared before writing. This leads to the fact that when writing to previously used blocks, the write speed drops greatly, 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 blocks on the disk are cleared. After all, there was no need for this on HDDs.

Therefore, when using SSD drives, the effect of "performance degradation" occurs. When the disk is new and all the blocks of flash memory are clean, the write speed is very high, certified. But after the disk is completely full and after that some of the files are deleted, rewriting 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.

The drop in write speed to reusable blocks of flash memory can be very high. Up to values \u200b\u200bclose to the recording speed of HDD disks. When testing SSD drives, they often even conduct a special test to reduce the write speed 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 deleting a file. At this command, the SSD disk controller flushes the freed blocks of flash memory, but does so in the background, between reads and writes.

Using this command returns the full write rate for reusable blocks of flash memory. However, not all operating systems support this command. But only relatively recent versions:

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

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

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

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

• Plextor M5 pro.
• Plextor M5S.

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

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

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

TRIM is most often disabled when using a RAID array.

SSD drives by manufacturer

Personally, I divide all SSD manufacturers into two categories - the G7 and everyone else. The Big Seven are Intel, Plextor, Corsair, Samsung, Micron (under the Crucial brand), Toshiba, SanDisk. Companies that sell good and great SSD drives. Each of them has its advantages, for example Intel, Samsung, Toshiba, SanDisk and Micron all make drives from their own flash memory. And Samsung uses not only its own memory in its SSD drives, but also its own controllers.

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

Everyone else is a pretty long list.

Intel... The company together with Micron produces flash memory. Thus, he makes his disks from his own memory and selects the best copies of memory for his disks. It is no coincidence that it gives a 5-year warranty on its drives. 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 drives are very good, but the company is mainly targeting the business segment and therefore its drives are quite expensive.

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

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

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 - both memory and controllers, all their own. As of the first half of 2014 model Samsung 840 Pro it is the fastest SSD in the consumer segment of the market (drives for conventional computers). The speed of this drive is already exhausting the capabilities of the SATA 3 interface.

Plextor... A Japanese company famous for its laser drives. In fact, the SSD does not make itself - Lite-On makes them for it. But the discs 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 remains one of the fastest SSD drives.

Corsair... The American company is known for the high quality of various products - random access memory, 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 drives on the SandForce controller, LS drives on the Phison controller, Neutron drives on the LAMD controller.

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

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

SSD disk lifespan

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

What does the write cycle limit mean in a practical sense? And how to roughly estimate the possible lifespan of this or that disk?

Let's take a conventional disk that uses MLC flash-memory produced according to the 19 nanometer process technology. Suppose 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 process technology.

Based on this memory, a 120 GB disk is made. The 3000 cycle limit means you can burn your entire disc 3000 times. If you fill it up completely every day, then clear it completely and fill it up again the next day, then theoretically the memory will live for 3000 days. That is, more than 8 years. If you write only 60 gigabytes a day and erase the disk only once every two days, then the lifespan increases to 16 years.

Of course this is simplistic. But it is clear that the lifespan 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 fills up completely 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 the manufacturers of flash memory specify write limits for their products.

And finally, many disk manufacturers explicitly state disk write limits in gigabytes per day in their disk specifications. For example, Samsung writes in the specifications of the 840 Pro disk: "A 5-year warranty is provided if the disk is written to a maximum of 40 gigabytes per day." Micron, for its Crucial M550 disc, specifies a recording limit of 72 terabytes, or about 66 gigabytes per day for three years.

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

How to extend the life of an SSD drive

Free disk space. Do not "clog" it completely - try to have 20 - 30 percent free space on the disk. Free space allows the controller to even out the wear of memory cells. It is better if this free space is unallocated, that is, it is not assigned to any partition with a file system.

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, keep an eye on the battery status - do not shut down the laptop due to the full discharge of the battery. SSD drives don't like sudden power outages. An abnormal power outage on the disk may damage data in the cells of the flash memory. Alternatively, you can buy a drive model that has Power Loss Protection.

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

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

A big plus is the aluminum SSD enclosure. If the drive is designed correctly, then the metal case is used as a heatsink to remove heat from the microcircuits.

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

High quality power supply. If you put the disk in a stationary computer, use a quality power supply. However, this point is relevant not only for extending the life of SSD drives, but also for all computer components in general. By the way, HDD drives don't like "bad" power supply either.

Don't defragment... Fragmentation of the file system does not slow down SSD performance. Therefore, by doing defragmentation, you will not get a gain in speed. However, defragmenting will shorten the life of the disk by increasing write operations.

Installing an SSD on an Old Motherboard

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

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

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

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

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

Common mistakes when using SSD drives

The first mistake

Moving a large number of files to 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.

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

Yes, and SSD space is saved and lifespan 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 OS and programs should be placed on an SSD drive. Working papers also need to be stored on an SSD drive. It makes sense to store only large data on the HDD - music, movies, images of laser discs, etc. And also data that is very rarely used - archives. Only then will you get the fastest speed from your SSD drive. Don't forget - the main reason for buying an SSD is speed! And that means you need to squeeze this speed to the maximum.

The second error

Disk Defragmenter. Out of the habit left over from using HDDs, people defragment SSDs as well. You don't need to do this! The speed of access to arbitrary data blocks in an SSD is about two orders of magnitude higher than in an HDD. Therefore, data fragmentation no longer affects the speed of reading this data.

Summary

Basic parameters of SSD drives

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

Secondary parameters of SSD drives

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

Which SSD drive to choose

Something like this:

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

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 read and write speed to date. A disk Intel S3500 will give the highest guarantee of data integrity and safety.

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 with a capacity of 120/128 GB will do.

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

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

If the computer stores and processes critical information that cannot be lost, then the best choice would probably be Intel S3500 or even Intel S3700.

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

Update 2016

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

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

Prices (dollar) go down, productivity goes up.

Another good piece of news relates to TLC drives. Such disks can have a lifespan comparable to MLC disks.

This became possible due to 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 MGX, SSD drives Samsung EVO 750 and 850.
• Marvell 88SS1074, SSD drives Plextor M7V.
• Silicon motion SM2256

According to the memory wear tests, the Samsung EVO 850 and Plextor M7V drives show very impressive results. On the level of good disks with MLC memory.

And the speed of work is 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 \u200b\u200b/ 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 the proprietary Samsung program):

• On a SATA 2 controller (Intel ICH9): 268 MB / s read and 250 MB / s write. This speed has been confirmed by measurement 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 against the limit of the SATA 2 standard itself. On SATA 3, the reading speed also rests on the limit of the standard. And at the same time, Samsung gives a 5-year warranty on the disks of the line EVO 850... And the result is an extremely fast and very reliable drive.

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

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

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

Update 2017

There are many M.2 SSDs on the market, priced comparable to 2.5 "SATA, but more importantly, there are M.2 motherboards.

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

Speed \u200b\u200bcloser to 1GB per second (or faster) depends on whether both the drive and the motherboard support NVM Express technology.

Before buying, you need to check 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 lines (2 or 4) must be connected to the M.2 connector.

Here are some M.2 motherboards with NVMe support for example:

• 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 OS version. 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 must use kernel version 3.13 19 or higher.

What is the benefit of using an NVMe-enabled SSD? At the minimum, for today, this is about twice the speed of work 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 get a motherboard and SSD with NVMe support.

Update 2018

Cheap Models

Many SSDs have appeared on sale with the lowest possible 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 DRAM cache. Such disks have a low price and nice numbers in terms of read and write speed, in the specifications.

The manufacturers of these SSDs draw pretty numbers on the specs 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 write speed. However, this only works as long as the write size does not exceed the size of this pseudo-SLC cache or until the disk is completely clogged so that there are no free slots for the pseudo-SLC cache. And then the disk gives out real, sad performance. Under high recording load, such drives can be even slower than HDDs.

And of course, given the weak processor of the controller and the absence of DRAM cache, such disks have low performance in the mode of access to arbitrary blocks with a queue depth of 1-4. And this is the most common operating mode for a disk in a home (not a game) and office computer.

Some of these models:

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

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

SATA goes down in history

Of course, SATA SSDs will be released for a long time. For replacing HDD in work 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 transfer 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 the M.2 NVMe SSD there. However, it should be noted that a motherboard with an M.2 connector, or an M.2 drive, may not have support for the NVMe protocol - in this case, the drive will operate at SATA3 (SATA mode).

3D XPoint (Intel Optane memory)

The first discs (from Intel) made on a new type of memory - 3D XPoint - appeared in retail. 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 writing. Third, it has a higher write resource.

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

The capacity of the first (for the retail market) 3D XPoint disks is not yet sufficient for their separate use (16 and 32 GB). And today Intel offers Optane memory technology for these drives. A 3D XPoint is installed in an M.2 slot and is used as a cache for a regular HDD. It seems to me that this is too difficult to implement and not an effective solution for the price. 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 and at a competitive (with NAND) price appear in retail.

Good and inexpensive SSD drives

SATA Intel SSD 545s - the minimum volume in this model line is 128 GB. The 256 GB model costs around 5500 rubles. The disk has - DDR3 DRAM cache, 64-layer TLC 3D V-NAND Intel - Micron, 4-channel SM2259 controller, aluminum case. For the 256 GB model, read and write speeds are stated: 550 and 500 megabytes per second. These are figures when using a pseudo-SLC cache, its size (in the 256 GB model) is 3 GB. Past the SLC cache, the write speed is around 400 MB per second. As of summer 2018, this is the best option in the budget segment.

SATA Samsung 850 MZ-7LN120BW - just 850 without the EVO suffix. There is only one model in the line, for 120 GB. It costs around 3,500 rubles. In this model, everything is adult - 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 writing is 75 Terabytes.

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

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

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

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

Assistant.ru, 2016, 2017, 2018

For those who do not like reading large texts, you can jump right to the conclusions - at the beginning of 2017, the Samsung 850 Evo SSD 256 or 512 gigabytes is still the best choice for most people. It's fast, reliable, comes with a long warranty, and comes with proprietary software to make it easy to switch from a regular drive to an SSD.

September 2018 update.: Samsung has released an update to all its SSDs this year Evo 860 and 860 Pro, transferring their production to new memory (64-layer TLC 3D V-NAND) and a new controller. However, from the point of view of the average user, the characteristics of the SSD have hardly changed, in some places they even become a little worse. Nevertheless, the price of the new SSDs remains the same, but the old models are simply sold out until they run out. Therefore, you can safely buy both the old and the new model. However, it's important to keep in mind that the new 860 series no longer has a 120GB SSD. Therefore, if you need just such an SSD, you should hurry up with the purchase. Because how to produce such SSDs?

And now about this in more detail.

Why should you trust me?

As I mentioned in the description of the site, I have been writing about technology for the last ten years, or even more. I spend even more time with this technique. This means that almost every day I try something new, adjust something, reconfigure, change, and so on in the same spirit. This text is a summary of my (and not only my, but also my colleagues') experience. So yes, you can trust me.

Who needsSSD?

If your computer or laptop is 3 to 5 years old (earlier models may contain SATA-II connectors, in which case the purchase should be considered separately, see the corresponding section below), and your system is based on a conventional hard disk, then it makes sense to think about buying an SSD. The dollar is pretty high right now, so you must have a good reason to buy it.

What does an SSD give? As a rule, it has three main advantages: almost instant loading of the operating system (less than 10 seconds), faster loading of files and programs, and less power consumption (the latter is relevant for laptops and allows them to run longer on battery power).

Thus, if the work of your computer is limited by the performance of the disk system, the purchase of an SSD is more than justified. With it, the system will simply "fly" and live much longer on battery power.

The picture above shows an example of just such a case. The bottleneck in this laptop is two elements - the power of the integrated video card (you can't do anything here) and the performance of the hard disk. The processor and memory are in complete order. After installing the SSD, the system will become noticeably faster.

To whomNo SSD needed?

If you have a relatively old computer (over 5 years old), or use an old SSD that is not very fast or has a small amount of memory, then there is little point in buying a new SSD. For this money, it is better to add memory or upgrade the processor. Or postpone for an upgrade. Yes, the system will load faster and files will open much better. But opening a simple browser will turn the computer into a pumpkin again.

Update as of July 27, 2016:in the comments, there is a regular controversy about whether it is possible to use an SSD for downloading torrents. Since opinions differ, let's listen to the manufacturers themselves. In a recent post on the Geektimes website (an iron project that broke away from the legendary Habrahabr), SSD manufacturer Kingston directly writes:

But to download torrents, if there is something to choose from, it is better after all to the hard disk. Because there are SUVs for fun and there are SUVs for driving in the mud. Here HDD is more likely to belong to the second category.

Those. everything is simple, if the SSD is the only disk in the system, then download it. You still have no choice. Moreover, this is a truly magical sight - to watch how the download speed does not rest against the capabilities of the hard disk, and reaches enormous values. But if you still have a hard disk in the system, then it is better to write torrents there. Because the SSD resource is not rubber, and regular download-delete-download still reduces it.

What volumeChoose an SSD?

For desktop computers, the minimum comfortable volume is 256 GB. It makes no sense to take less for two reasons:

1. Typically, 128GB models operate at noticeably slower write and read speeds.
2. In order for an SSD to work for a long time and reliably, at least 30% of free space must remain on it. This is due to the fact that the disk controller must evenly distribute the load between the memory cells for its even wear.

Thus, 256 GB is the minimum SSD storage for a desktop computer. A traditional hard drive can be used to store files that do not require daily access (see).

With a laptop, things are a little more complicated. Since many laptops do not allow you to put both an SSD disk and a hard disk at the same time, the entire amount of information will have to be stored on the SSD. Therefore, 512 GB is the optimal solution that will suit most users. Alas, the price of such a disk turns out to be impressive, but you get quick access to all files and noticeable savings in battery life. By the way, if your laptop for some reason has a DVD-ROM, you can dismantle it (this is done very simply) and replace it with a hard drive bay. In this case, you can replace the standard disk with an SSD, and instead of a DVD, connect an old disk. Thus, you will speed up the system and increase the place.

Does it make sense to buy a SATA-2 SSD?

Judging by the comments, this point should be discussed separately. So, if your motherboard supports SATA3, then the interface bandwidth is 6 Gb / s, SATA2 - only 3 Gb / s. Those. it would seem a twofold difference. However, as we said in the section on flash drives, it is not the linear speed that is important, but the speed of reading scattered files. Because when loading, the system collects the OS in separate files, smeared all over the drive at random.

In order to answer the question whether it is necessary to install a modern SSD-drive into a system with SATA2, let us turn to a thorough article from the THG.RU resource. The authors sequentially connected the Samsung 840 PRO drive, by the way, an excellent SSD of the previous generation, to the SATA2 and 3. To have something to compare with, the third in the test was a very fast WD VelociRaptor hard drive. If you look at the linear read and write speed graph, the advantage of SATA 3 is more than noticeable.

Please note - in this case, the HDD practically does not lag behind the SSD connected via SATA-2. However, as we understand it, linear write and read speed is not that important. In a real situation, we are more interested in the speed of an arbitrary (random sector). Let's see how disks behave with a random sector size of 512 Kb.

As you can see, the difference is also twofold, while the hard drive starts to lag behind. If we make the sector size in 4Kb, then the difference between SATA will practically disappear, but the HDD will generally become very slow. What does this lead to? To the fact that, say, booting your operating system from an HDD will take noticeably longer than from an SSD. Moreover, the difference in connection will not play a role. Windows will boot up almost equally quickly.

What conclusion can be drawn? Everything is very simple - if you use an SSD exclusively as a boot and system one, there will not be much difference between SATA-2 and SATA-3. Both interfaces allow you to load quickly enough. And the purchase of an SSD is justified even in this case.

And here's the fun part: if you have an old computer with only SATA-2, then you hardly need a modern high-speed SSD. Your problem is not with him. Yes, the system will boot noticeably faster. But the performance itself ... Let's just say that for this money it is easier to buy additional memory and upgrade the motherboard and processor. The difference will be noticeable even on an old HDD. But if you have reached the bottleneck in terms of hard drive performance, and you do not want to spend money on a significant upgrade, then yes, you can look at the purchase. But, again, it's better to think about upgrading your computer, and then go here and choose a modern SSD that will 100% unleash the potential of your system.

WhatIs the SSD better to choose?

At the moment, your best bet is to buy a Samsung 850 EVO SSD of the size you need (or a similar Samsung 860 EVO). At the start of sales, it was quite expensive, but now prices in dollars have dropped slightly and the price has become more or less acceptable.

Why 850 or 860 EVO? The point is that most modern user-grade SSDs have similar specifications. Trust me, if you are not an SSD specialist, then in most cases you will not notice the difference in performance between different models. Between the hard drive and the SSD, notice a significant one. But between different SSD models - no.

Then what comes to the fore if not speed? These are price, reliability, the ability to survive a large number of write cycles, the quality of the controller, the quality of the firmware and proprietary software that makes life easier for the user.

In this regard, the Samsung 850 EVO currently has virtually no competitors.

• It is relatively inexpensive (at the time of publication, on average, 8 thousand for a volume of 256 GB and 12 thousand for 500 GB);
• it is fast (on average 516 Mb / s for reading and 426 Mb / s for writing);
• it is reliable (Samsung itself is the manufacturer of both memory and controller);
• it can pump up to 150 Tb of data through itself (this is a very large amount of data for most users);
• it has a 5-year warranty.

In addition, if you use Windows, the bundle includes proprietary software that allows, firstly, it is convenient to migrate from a hard drive to an SSD, and secondly, and this is the most pleasant thing, to use up to 4 GB of RAM as a cache for the disk. This makes working with the disc even faster.

Another plus for the purchase can be the presence of hardware data encryption. Most users do not need this at all, but for some it may be critical.

And if there is no noticeable difference in speed, is there something cheaper?

If the price of the Samsung 850 EVO seems too expensive for you, then I would put the Crucial BX100 in second place.

It costs 2 thousand rubles less. He's fast too, he's reliable too.

In fact, for a slightly lower price, you get a slightly lower warranty - only three years, less data that can be pumped through the disk (72 TB instead of 150 for Samsung, although this value is enough for the eyes). In addition, it doesn't have the same software bundled as the 850 EVO. But no one bothers you to use third-party programs, of which there are quite a few. You just have to tinker a bit with the setup.

So, if that doesn't scare you, the Crucial BX100 is a great alternative to the 850 EVO. Moreover, Crucial BX100 consumes less energy and the laptop will live with it at least a little bit, but longer (about 10 minutes).

M.2 SSD

Despite the fact that M.2 slots appear in more and more laptops, motherboards, and a) can be faster than a regular SSD, b) they allow you to use both SSD for Windows and HDD for storing files at the same time, it is very difficult to advise something here ... The fact is that at the moment there are two varieties of the M.2 standard. These are M.2 SATA and M.2 PCI. Each of them is divided into several more sub-standards depending on the physical size, and M.2 PCI, in addition, is also divided into several sub-standards, depending on the number of PCI lanes connected.

Those. you can't just go to a store and buy an M.2 disc there. First you need to study the documentation of your laptop or motherboard, understand which of the standards suits you, and only then buy something specific. Therefore, I repeat, it is very difficult to advise something specific here. If you are still determined to buy an M.2 SSD, I advise you to go to this one of our site, where we tried to collect the most complete information on the compatibility of various drives with different hardware. And already based on the data received, select a specific model.

If you have M.2 SATA 2280 in size, then you can not philosophize and take the same Samsung 850 EVO in M.2 format. In all other cases, you will have to look carefully.

SSD for professionals

If your job involves processing a lot of raw RAW photos, or you are constantly editing large volumes of video, working with 3D graphics, a fan of daily heavy torrents, or running multiple virtual machines at the same time, then a regular SSD is not for you. In this case, I would pay attention to the Samsung 850 Pro version.

Why is it better. First, it is faster. This is actually noticeable when working with large files in random read mode. In normal operation, the difference is not noticeable, but in professional use, the difference can be felt. Secondly, it has a 10-year warranty. Thirdly, it was originally designed for such a tough operating mode and has the corresponding reliability. In fact, it has no competitors in its class. The price, unfortunately, is also 30% higher: 256 gigabytes cost 10-11 thousand rubles, 500 GB - about 16 thousand.

Who else loves the Samsung Evo SSD?

As you can see, the Samsung 850 EVO is the top choice in terms of price / performance ratio. Several quotes from the reviewers:

• Samsung 850PRO... It is the most productive and most technologically advanced SATA SSD, based on the unique 3D MLC V-NAND. In addition to outstanding performance, this model also stands out for its high reliability, which is backed by a 10-year warranty. In addition, the Samsung 850 PRO boasts a whole bunch of different niceties, such as support for OS-managed encryption and an excellent tool utility.
• Samsung 850 EVO... The younger brother of the invincible 850 PRO also stands out from the competition. Yes, it is based on TLC V-NAND and therefore gives a lower performance during write operations, but this does not prevent it from remaining one of the best SSDs in terms of weighted average performance and occupying a leading position in the mid-price category. In addition, the 850 EVO inherits from the 850 PRO the entire proprietary set of additional advantages: encryption support, high-quality software, and more.

Now a solid-state drive is no longer a privilege of expensive laptops, but an almost mandatory component even for models for 60 thousand rubles. Nevertheless, if you ask yourself such a question, then the most interesting thing is still ahead.

As Confucius said: "One has only to work on a computer with an SSD once, and there will be no turning back." If in the past decade everyone was chasing hundreds and thousands of megahertz, then with the advent of the SSD, it became obvious that the bottleneck was a drive, not a processor.

If your laptop with a quad-core i7 boots Windows and runs applications for a minute or more, the problem is definitely a slow hard drive, and not at all in the processor. With an SSD, everything starts in a matter of seconds, files are opened and saved instantly. As a result, work becomes much more pleasant. So let's be honest: The only way you don't need an SSD is if you already have one.

SSDs are expensive, aren't they?

Hard drives are still noticeably cheaper than SSDs based on the price of one megabyte, that's a fact. But in most cases you do not need a volumetric "solid state". You can always watch TV shows online, store photos - in the bottomless storage of Yandex.Disk, Google Drive or Dropbox, listen to music - from countless streaming services, domestic or foreign.

So it turns out that quite often users on a laptop actually do not have much information, and the main thing can be fit on a quite inexpensive SSD. However, on a gaming laptop, everything is not so simple. Of course, I would like to install all the toys on the "solid state", so that the maps in Battlefield are loaded not so painfully long. Unfortunately, modern games consume too much space to be installed on inexpensive solid state machines. But there are options described in the next paragraph.

Where will I store terabytes of photos from my last vacation in Tenerife?

External hard drive

And even if your laptop is packed with media files to the eyeballs, it's still not a reason to refuse to purchase an SSD. Even a small volume is enough to install the operating system, browser and other essential programs. And then you won't recognize your laptop.

Moreover, it is not at all necessary to give up a hard drive with hundreds of gigabytes of good acquired by back-breaking labor. Firstly, there are quite a few laptops with space for both a fast "solid state" and a large hard drive. Secondly, even if you have a super-thin ultrabook, this is not a problem - external hard drives have been on sale for a long time. And even hard drives with Wi-Fi for those who don't like wires. Or, again, you can rent yourself a place in the cloud. Although, if you plan to use it as a balcony or garage, that is, look only once a year or less often and put everything that is a pity to throw there, then it's better to take an external hard drive.

Can I install an SSD in my laptop?

In most cases, the answer is yes. It is definitely impossible to install a "solid-state device" only in laptops, in which it is already soldered right on the motherboard. But the cases when the laptop already has an SSD, we are not very interested in this material.

If you have only one slot for drives in your laptop, and it is already occupied by a hard drive, then the best option is to buy a solid-state drive to replace the hard drive, and for the hard drive to purchase a special container with an adapter to make a convenient external hard drive out of this hard drive. So you solve the problem with the speed of the system and with the storage of a large amount of data. And, in fact, you do not lose anything.

Either way, you'll have to start by figuring out how many drives you can install in your laptop and what type they are. There are not so many variations, but enough to confuse an inexperienced person. Therefore, it is best to search forums for specific models, where people have already figured out which drives can be installed in this or that laptop model.

Which to choose?

Form factor

M.2 SSD (top) and 2.5 '' SATA SSD (bottom)

The choice of form factor does not depend on you, but on your laptop. Older models only support 2.5-inch SATA drives. They are not as fast as some modern M.2 solid state machines. Most of the time, buying them is just a necessity, if the laptop does not include M.2.

Nevertheless, the performance of a high-quality 2.5-inch "solid-state device" is more than enough for everyday needs, and even more so for a person who has never dealt with an SSD before. Moreover, the M.2 connector itself is not an indicator of drive performance, and even slower models are quietly found among SSDs with M.2.

However, the fastest of the M.2s are five times faster than the standard 2.5-inch. But the point here is not even the name of the connector, but the data transfer interface. Faster SSDs are indicated by the abbreviation PCIe 3.0 (or NVMe), but we will not dwell on such subtleties in detail.

Volume

Anything less than 120 GB is not worth attention at all - nothing will fit in there, and you will just experience constant pain. The exceptions are all sorts of Chromebooks with 32 and 64 GB drives, but often these are not even SSDs, but devices with slow memory and sluggish controllers that work even slower than hard drives.

You can live with a 120GB drive, but only if you don't really store a lot of programs and files. Otherwise, it is better to pay attention to the 256 GB models.

Finally, 512 and 1024 GB are desirable numbers for many, but the cost of such drives in retail is high, and the surcharge for modifying a laptop with similar ones is even higher. You can even put video games there, or, for example, two operating systems, each with its own set of programs and files, and much of everything else that your imagination is capable of.

The cost

Let's move on to the unpleasant part. Prices for 256 GB solid-state drives, be they at least 2.5 ", even M.2, start at about 6,000 rubles. 512 GB - from 10 thousand rubles. Of course, these are starting prices, and, depending on the performance of the drive or just the impudence of the brand, they can be one and a half to two times higher for a model of the same size. Whether the model is worth its money or not - this, unfortunately, can only be found from reviews or discussions on the forums. Or from reviews in stores, if only you can read these reviews correctly.