What is ssd. SSD disk - what is it and what it is eaten with. The use of SSD drives

Until recently, data storage media used the magnetic recording principle. In the 70s and 80s of the past century, they were floppy disks, which then gave way to more reliable and capacious hard drives. This state of affairs was observed until the end of the last decade, until SSDs appeared on the market - solid-state electronic media devoid of moving mechanical parts and characterized by high performance.

At first, they were distinguished by their small capacity and high price. The service life of these devices also left much to be desired. Therefore, there was no definite answer to the question of why you need an SSD drive. With a volume of 32 or 64 GB and a price of several hundred dollars, these media seemed to most of the expensive toys. And a slight advantage in read / write speed (up to 1.5-2 times) made SSDs interesting only for geeks seeking to squeeze the maximum performance out of their PC.

But progress does not stand still, and soon larger and more affordable solid-state drives went on sale, which attracted the attention of a wide audience. The question of why you need an SSD hard drive has become more relevant than ever.

Design features, advantages of SSD drives

To understand why to install an SSD drive, you need to understand the main advantages of such drives. It does not hurt to know the main disadvantages of these gadgets.

HDD and SSD drive design

The main difference between SSDs and traditional hard drives is the different principle of design and operation. Unlike HDDs, there are no mechanical components in the construction of solid-state media. To write data, arrays of high-speed flash memory are used, access to which is provided by an internal controller. This design gives the SSD a number of advantages not available with traditional HDDs.

• Noiselessness... Due to the absence of moving elements, the SSD does not emit sounds during operation.
• Shock resistant... Unlike HDDs, where in the process of moving the device or falling, the magnetic head can scratch the surface of the disk (thereby damaging it and the stored data), the SSD is less vulnerable. Of course, as a result of a blow to the case, contact between the components may be disrupted, but a drive hidden inside a computer or laptop is sufficiently protected from this.
• Low power consumption... The main consumer of energy in a railway is the motor driving the disks. It rotates at a speed of 5, 7, or 10 thousand revolutions per minute and consumes up to 95% of all the electricity supplied to the drive. Thus, SSD is up to 10 times more economical, which is especially true for thin laptops.
• High read / write speed... The magnetic method of recording data has reached the limit of perfection. More than 100-200 MB / s in sequential write mode, without reducing the service life, increasing dimensions, increasing power consumption and increasing prices, cannot be obtained from a hard disk. SSD flash memory does not have this disadvantage and is up to 10 times faster.
• Stable working speed... If information on a traditional hard disk drive is recorded on physically different disks (their designs are HDDs 2 or more) or their sections, a delay occurs due to the need to move the read head. Because of this, the speed of work is significantly reduced. A similar latency in reading cells in an SSD flash array is in the millionths of a second and does not significantly affect overall performance.

Disadvantages of SSD

With all the advantages, it's too early to talk about the perfection of SSD technology. The disadvantages of such drives are insufficiently low cost (3-10 times more expensive than HDD in terms of 1 GB of memory) and limited service life (from 10 thousand to 1 million rewriting cycles per cell). This indicator for HDD is theoretically unlimited, but in practice it reaches tens of millions of cycles.

Another disadvantage of solid-state drives is electrical vulnerability: when a high voltage is applied, caused by a malfunctioning power supply, both the controller and the flash drive burn out.

SSD drives - why are they needed

Knowing the main advantages of solid-state drives, answer the question “Why do you need SSD disk into the computer? " much easier. The purchase of this gadget will allow, first of all, to increase the comfort of using the gadget and extend its time autonomous work (if it is a laptop). High operating speed will have a positive effect on OS boot time, opening documents and performance in games.

Why an SSD is needed in a laptop

If it comes to a laptop, then the question "why do we need an SSD" can be omitted at all. In any case, buying a solid state drive won't make it any worse. Energy-efficient technology will allow you to achieve longer runtime on a single charge, the absence of high voltage in the power supply circuits minimizes the risk of irreparable damage to the drive in the event of a power supply failure, and the memory capacity in a laptop does not play as important a role as in a desktop PC.

As for the smaller resource of work, experience service centers shows: laptop hard drive fails and undergoes premature wear several times more often and faster than in desktop computer... This is due, first of all, to a significantly larger amount of dynamic loads that the device is subjected to during transportation and operation. Accidentally dropping a laptop from your knees at the moment when data is being written to the HDD, there is a high risk of damaging the drive, even if the computer was not visually damaged. Therefore, it is highly likely that an SSD will last even longer than a hard disk drive.

Why SSD drive in a gaming PC

Gamers are the majority of SSD buyers at the moment. Application solid state drive allows them to achieve better performance in 3D games by reducing the launch time. Loading levels, inventory, surrounding objects and other elements of the game world from files stored on disk is also significantly (up to 10 times) faster.

There is a noticeable difference in seamless games like Skyrim, Grand theft Auto or Fallout. The inner world in them is located on one huge map, and to reduce the load on hardware, only a part of it is stored in RAM. This can be the environment, for example, within a radius of 200 meters around the character. As you move through the terrain, objects moving away from the RAM are removed, and in their place objects are written in the direction of which the player approaches. Thus, reading from the hard disk occurs constantly and it is easy to guess that the SSD will allow the processor to supply data much faster and more efficiently than the hard disk drive.

For gamers, the high cost per gigabyte in an SSD is not critical, since games take up relatively little space. If a collection of 100 films in FullHD quality weighs about 1 TB, the same Fallout 4 requires less than 50 GB of free space.

Why you need an SSD hard drive in a multimedia computer

In a home PC used for surfing the web and solving multimedia tasks (watching movies, listening to music), the SSD is the least needed. The need for such a disc can only be experienced by connoisseurs of content in the quality of Blue-Ray. It takes a long time (about 10 minutes) to wait for a 40 GB movie to be written to the PC memory. But to store a selection of your favorite movies in FullHD, QHD or 4K UHD, you need a spacious SSD of 500, 1000 or 2000 GB. The cost of such drives exceeds a thousand dollars, and not everyone can afford such an acquisition.

For undemanding PC users, a large SSD in a multimedia computer is unnecessary. The capabilities of classic (magnetic) hard drives are enough to meet the needs of 99% of users. However, a small (64 - 128 GB) solid state drive used as system media (for installing Windows) will not be superfluous. It will significantly improve the overall performance of the PC, reduce noise system unit and more economical use of electricity.

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I recommend purchasing an SSD drive with an optimal speed / reliability ratio of MLC or 3D NAND memory. Read / write speed closer to 500/500 MB / s is considered high enough. The minimum recommended speed for more budget SSDs is 450/300 MB / s.

The best brands are Intel, Samsung, Crucial and SanDisk. As a more budgetary option, you can consider: Plextor, Corsair and A-DATA. Problematic models are more common among other manufacturers.

For a work or multimedia computer (video, simple games), an SSD with a capacity of 120-128 GB will be enough, and here A-Data Ultimate SU900 on MLC memory will be an excellent choice.
SSD A-Data Ultimate SU900 128GB

For a mid-range gaming computer, you need at least 240-256 GB, and an SSD from the A-Data Ultimate SU900 or Samsung 860 EVO series is also suitable.
SSD A-Data Ultimate SU900 256GB

SSD Samsung MZ-76E250BW

For a professional or powerful gaming computer, it is better to take a 480-512 GB SSD, for example the Samsung SSD 860 EVO.
SSD Samsung MZ-76E500BW

For computers and laptops with an M.2 connector, a super-fast SSD (1500-3000 MB / s) in the appropriate format is a good option.
SSD Samsung MZ-V7E500BW

When choosing a volume, you are guided by your needs, but you should not neglect it for the sake of higher speed. If you doubt the correctness of your choice, we recommend reading reviews of specific models.

2. What is the difference between expensive and cheap SSD

Inexperienced users may be puzzled why SSD drives of the same volume, with the same declared speed characteristics, differ so much in price, sometimes several times.

The fact is that different types of memory can be used in different SSD drives, which, in addition to speed indicators, also affects reliability and durability. In addition, memory chips from different manufacturers also differ in quality. Naturally, cheap SSDs are equipped with the cheapest memory chips.

In addition to memory chips, an SSD disk has a so-called controller. This is a microcircuit that controls the processes of reading / writing data to memory chips. Controllers are also produced by different companies and they can be either budgetary with lower speed and reliability, or higher quality. Cheap SSDs, as you know, also have the worst controllers.

Many modern SSDs use fast DDR3 memory as a clipboard to further improve performance, just like a computer's RAM. Most budget SSDs may not have a clipboard, making them marginally cheaper, but significantly slower.

But that's not all, it even comes down to saving on such important components of an SSD drive as capacitors, which are necessary to prevent integrity violations and data loss. In the event of a sudden power outage, the electrical energy stored in the capacitors is used to complete the clipboard recording to the memory chips. Unfortunately, not all even high-quality SSDs are equipped with backup capacitors.

The layout itself and the quality of the PCB wiring are also different. More expensive models have more sophisticated circuitry, quality of the element base and wiring. The engineering solutions for the lowest-cost SSDs are based on outdated circuits and leave much to be desired. Low-cost SSDs are also more rejected due to assembly in cheaper factories and lower levels of production control.

And of course the price depends on the brand, the more famous it is, the more expensive the SSD. Hence, there is an opinion that you should not overpay for the brand. But the fact is that often it is the brand name that determines the quality of an SSD drive. Most well-known manufacturers who value their reputation will not allow themselves to produce low-quality products. However, there are exceptions here, in the form of well-known and popular brands, which, nevertheless, should not be recommended for purchase.

The main differences between SSDs, which you need to focus on, we will briefly understand in this article and you can easily choose the model that suits you.

3. VolumeSSDdisk

Volume is the most important parameter of an SSD drive.

If you only need an SSD for acceleration windows boot, office programs and increasing the responsiveness of the system, then, in principle, a volume of 60-64 GB (gigabytes) will be enough.

If you want to speed up the work of serious professional applications (video editing, design systems, etc.), then you need a 120-128 GB SSD disk.

For a gaming computer, it is advisable to purchase an SSD with a volume of at least 240-256 GB, since modern games take up a lot of space (30-60 GB each).

In the future, focus on your needs (how much space you need for your programs, games, etc.) and financial capabilities. It is not advisable to use an SSD for data storage, for this you need a more capacious and cheaper hard disk drive (HDD) with a volume of 1-4 TB (1000-4000 GB).

4. SSD read / write speed

The main indicators sSD speed disk read speed, write speed and access time.

According to statistics, the number of read operations on ordinary computers of users is 20 times greater than the number of write operations. Therefore, reading speed is a much more important characteristic for us.

The read speed of most modern SSDs is in the range of 450-550 MB / s (megabytes per second). The higher this value, the better, but 450 MB / s is, in principle, quite enough, and taking an SSD with a lower read speed is impractical, since the price difference will be insignificant. But do not blindly trust the representatives of budget brands, as the speed of cheap SSDs can drop significantly as the disk space fills up. The speed of a particular SSD model in real conditions can be found from tests on the Internet.

Most SSDs have write speeds in the 350-550 MB / s range. Again, the faster the better, this is understandable. But due to the fact that write operations are performed 20 times less frequently than read operations, this indicator is not so critical and the difference will not be very noticeable for most users. But the price of discs with a higher write speed will be noticeably higher. Therefore, 350 MB / s can be taken as the minimum record speed. Purchasing an SSD with an even lower write speed will not bring significant savings, so it is impractical. Please note that some manufacturers specify write speed for the entire line of SSD drives, which have different capacities. For example, Transcend's SSD370S line has drives ranging from 32GB to 1024GB. The write speed for the entire line is indicated at 460 Mb / s. But in fact, only 512 and 1024 GB models have this speed. The photo below shows a fragment of the Transcend SSD370S package with a capacity of 256 GB with a real write speed of 370 MB / s.

The access time determines how fast the disk finds the required file after receiving a request from a program or operating system. For conventional hard drives, this figure is in the range of 10-19 ms (milliseconds) and significantly affects the responsiveness of the system and the speed of copying small files. SSD drives, due to the absence of moving parts, have access speeds up to 100 times higher. Therefore, this parameter is usually not focused on, any SSD provides an incredibly high access speed. Nevertheless, higher quality models can have access times of the order of 0.1 ms, and the most budgetary models can have 0.4 ms. The difference in access time by 4 times does not speak in favor of budget SSDs. With this parameter, budget SSD manufacturers can also be cunning and indicate the theoretical value under ideal conditions.

You can find out the real speed characteristics of SSD drives from tests on the most reputable technical portals. You can download a file with links to them at the end of the article in the "" section.

5. Types of memory and SSD resource

Modern SSD drives use several types of memory - MLC, TLC and 3D NAND (V-NAND).

MLC is the most popular type of memory for SSD drives with an optimal price / speed / durability ratio and an estimated resource of 3000-5000 rewriting cycles.

TLC is a cheaper type of memory found in budget SSDs, with a rewrite resource of about 1000 cycles.

3D NAND is a modern fast memory developed by Samsung with the highest rewritability. Fits into more expensive Samsung SSD models.

There is a myth that SSD drives wear out very quickly. Therefore, you need to choose models with the maximum possible resource and use all sorts of tricks in the operating system settings to extend the service life of the SSD disk, otherwise it will quickly work out its resource and fail.

In fact, the resource of modern SSDs matters only when they are installed in servers where the disks are worn out around the clock. In such conditions, due to the colossal number of rewriting cycles, SSDs really serve an order of magnitude less than their older brothers - mechanical hard drives. But we already know that in computers of ordinary users the number of write operations, due to which wear and tear occurs, is 20 times lower than read operations. Therefore, even with a relatively heavy load, the resource of any modern SSD will allow it to work for 10 or more years.

Despite the fact that the data on rapid wear is highly exaggerated, it is not worth purchasing an SSD based on the cheapest TLC memory, as the savings will be insignificant. For today, the best option would be an SSD disk with MLC memory. And the actual lifespan of an SSD drive will depend more on the quality of production and. Pay more attention to brand and warranty period.

6. Clipboard

A clipboard (cache) based on DDR3 memory speeds up the performance of an SSD drive, but makes it somewhat more expensive. For every 1 GB of SSD storage, there must be 1 MB of DDR3 cache. Thus, a 120-128 GB SSD must have 128 MB DDR3, 240-256 GB - 256 MB DDR3, 500-512 GB - 512 MB DDR3, 960-1024 GB - 1024 MB DDR3.

Some models have older DDR2 memory caches, but this does not significantly affect performance.

7. Protection against blackout

It is desirable that a disk with DDR3 cache memory has Power Protection, which is usually based on tantalum capacitors and allows data from the buffer to be saved to memory chips in the event of a power outage of the SSD. But if you have an uninterruptible power supply (UPS, UPS), then power failure protection can be neglected.

SSDs with no DDR3 memory cache do not require additional protection against power outages.

8. SSD controllers

There are many controllers for SSD drives. The most popular brands are Intel, Samsung, Marvell, SandForce, Phison, JMicron, Silicon Motion, Indilinx (OCZ, Toshiba).

The best SSD drives are built on Intel, Samsung, Marvell controllers. In the middle class, the more popular SandForce controllers and the younger Phison controllers are more popular. Inexpensive SSD models are often content with older budget JMicron controllers and younger Silicon Motion controllers. Indilinx made fairly reliable controllers and was bought out by OCZ and then Toshiba for use in their mid-range SSDs.

But each manufacturer has both cheaper and more expensive controllers. Therefore, you need to navigate by a specific controller model, an overview of which is easy to find on the Internet.

Most of the controllers in entry and mid-range SSDs are 4-channel. Top SSD models are equipped with faster and more modern 8-channel controllers. But don't bother too much with controller models, it's not always easy to figure it out. Focus primarily on the brand, the declared characteristics of the SSD drive and real tests of a specific model, which often also consider the advantages and disadvantages of the installed controller and other electronic filling of the SSD.

In addition to the read / write speed, the controller also depends on the support of various technologies designed to improve the operation of the SSD disk.

9. Supported technologies and TRIM function

An SSD drive, depending on the model and the controller installed in it, can support various technologies designed to improve its performance. Many manufacturers develop their proprietary technologies that provide more marketing value than actual value to users. I will not list them, this information is in the descriptions of specific models.

The most important feature that any modern SSD should support is TRIM (garbage collection). Her job is as follows. An SSD can only write data to free memory locations. As long as there are enough free cells, the SSD disk writes data to them. As soon as there are few free cells, the SSD needs to clear cells, data from which are no longer needed (the file has been deleted). A non-TRIM SSD clears these cells just before new data is written, which significantly increases the write operation time. It turns out that as the disk fills up, the write speed degrades. An SSD with TRIM support, having received a notification from the operating system about data deletion, also marks the cells in which they were unused, but clears them not before writing new data, but in advance in free time (when the disk is not used very actively). This is called garbage collection. As a result, the write speed is always kept at the highest possible level.

10. SSD hidden area

Each SSD has a fairly large amount of memory in a hidden (inaccessible to the user) area. These cells are used instead of failing ones, due to which the volume of the disk is not lost over time and the safety of the data that is previously transferred by the disk from the “sick” cells to the “healthy” ones is ensured.

In high-quality SSDs, this hidden volume can reach 30% of the declared disk size. Some manufacturers, in order to save money and gain a competitive advantage, make the hidden disk volume less (up to 10%), and user accessible more. Thanks to this, the user gets more available volume for the same money.

But there is another negative side to this manufacturer's trick. The fact is that the hidden area is used not only as an inviolable reserve, but also for the TRIM function. Too small amount of the hidden area leads to insufficient memory required for background data transfer (garbage cleaning) and the speed of the SSD disk at high occupancy (80-90%) degrades greatly, sometimes several times. This is the price of the "free" additional volume and that is why high-quality SSD drives have a large hidden area.

TRIM must be supported by the operating system. All versions starting from Windows 7 support the TRIM function.

11. SSD manufacturers

The best manufacturer of SSD drives is Intel, but their cost is very high and they are used mainly in the corporate sector for mission-critical systems and servers.

The next leader in terms of technology is Samsung. Their SSDs cost more than the rest on average, but are of impeccable quality, reliability and speed.

The SSD brands Crucial, Plextor (a Samsung trademark) and SanDisk were recognized as the best in terms of price / quality ratio.

Also, as a compromise option in terms of price / quality, you can consider the SSD of the proven Corsair brand and A-DATA.

I do not recommend purchasing SSDs sold under the Kingston brand, as most of them do not meet the declared characteristics and their speed degrades greatly as they fill up. But this manufacturer also has SSDs from the top-end HyperX series, which differ more high quality and they may well be considered as an alternative to top expensive brands.

In general, budget and unpopular brands - like a lottery, may or may not be lucky. Therefore, I recommend that you refuse to purchase them if possible. And on the model of the recommended brands it is still better to look for reviews, since “there is a hole in the old woman”. I remind you that links to reviews of SSD drives are in the file, which can be downloaded in the "" section.

12. SSD form factor and interface

The most popular today are 2.5 ″ form factor SSDs with a SATA3 (6 Gb / s) interface connector.

Such an SSD can be installed in a computer or laptop. The motherboard or laptop must have a SATA3 (6Gb / s) or SATA2 (3Gb / s) connector. Correct operation when connected to the first version of SATA (1.5 Gb / s) is possible but not guaranteed.

When connected to the SATA2 connector, the read / write speed of the SSD will be capped at around 280MB / s. But you will still get a significant performance boost over a conventional hard disk drive (HDD).

Plus, the access time will not go anywhere, which is 100 times lower than that of HDD, which will also significantly increase the responsiveness of the system and programs.

The more compact SSD form factor is mSATA, which is based on the SATA bus but has a different connector.

The use of such an SSD is justified in ultra-compact computers, laptops and mobile devices (tablets) with an mSATA connector, in which the installation of a conventional SSD is impossible or undesirable.

Another more compact SSD form factor is M.2. This connector replaces mSATA, but is based on the faster PCI-E bus.

Motherboard, laptop or mobile device (tablet) must also have an appropriate connector.

Well, another type of SSD is presented in the form of a PCI-E expansion card.

Such SSDs have a very high speed (3-10 times higher than SSDs with SATA3 interface), but they are much more expensive and therefore are used mainly in very demanding professional tasks.

13. Body material

An SSD enclosure is usually made of plastic or aluminum. It is believed that aluminum is better because it has a higher thermal conductivity. But since the SSD does not heat up significantly, this does not really matter and may not be taken into account when choosing a model.

14. Package contents

If you are purchasing an SSD for a computer and the case does not have mounts for 2.5 ″ drives, then pay attention to the presence of a mounting frame in the kit.

Most SSDs do not come with a mounting frame or even screws. But the included screw mount can be purchased separately.

The presence of a mount shouldn't be a weighty criterion when choosing an SSD, but sometimes a better SSD bundled with a mount can be purchased for the same money as a budget SSD with a separate mount.

15. Setting up filters in the online store

1. Go to the "SSD drives" section on the seller's website.
2. Select the recommended manufacturers (Crucial, Plextor, Samsung, SanDisk), you can also consider Corsair and A-DATA.
3. Select the size you want (120-128, 240-256 GB).
4. Sort the sample by price.
5. Browse SSDs starting with the cheaper ones.
6. Choose several models suitable for the price and speed (from 450/350 Mb / s).
7. Search online for their reviews and buy the best model.

Thus, you will get an SSD disk that is optimal in terms of volume and speed, meeting high quality criteria, at the lowest possible cost.

16. Links

SSD Samsung MZ-76E250BW
SSD A-Data Ultimate SU650 240GB
SSD A-Data Ultimate SU650 120GB

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 so much that they can be considered as a reasonable alternative to hard disk drives (HDD).

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 another

SSD 2.5 ″

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

2.5 ″ SSD compatibility with computers

SSD of this form factor can be installed in any desktop computer or a laptop with a free 2.5-inch drive bay. If your system only has room for the old 3.5 '' hard disk, it can also fit a 2.5 ″ SSD. But in this case, look for an SSD model that comes with a special latch.

Like modern HDDs, a 2.5 ″ SSD is connected to the motherboard using sATA interface3. This connection provides a throughput of up to 600 MB / s. If you have an older motherboard with a SATA2 connector, you can still plug in a 2.5 ″ SSD, but the storage bandwidth will be limited old version interface.

SSD M.2

More compact form factor, due to which it is suitable even for especially thin ones, in which there is no room 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.

To connect to the board, each M.2 drive uses one of two interfaces: 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.

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

M.2 SSD Compatibility with Computers

Before purchasing an M.2 SSD, you need to make sure that it will fit your motherboard. To do this, first check the physical and then 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 for connecting M.2 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 notches at once, less often only one of two keys: B or M.

The B-connector on the board can be connected with a B-connector. To the M-slot, respectively, a drive with a M. SSD type connector, 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 with B + M key (upper) and M.2 SSD with M key (lower) / www.wdc.com

So, first make sure your motherboard has an M.2 SSD connector at all. Then find out the key of your connector and select the drive, the connector of which 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

For an SSD to fit your motherboard, it is not enough to take into account the physical compatibility of its connector with the connector. The point is that the drive connector may not support the logical interface (protocol) that is used in the slot of your board.

Therefore, when you understand 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 the supported protocols.

3. Dimensional compatibility

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

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

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

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

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

Less popular form factors

Your computer case may not have a 2.5 ”SSD bay, and your motherboard will not have an M.2 slot. The owner of a thin laptop may face such an atypical situation. Then for your system you need to choose SSD 1,8 ″ or mSATA - check in the documents for your computer. These are rare form factors that are more compact than a 2.5 ”SSD, but are not as fast as M.2 drives.

Plus, Apple's thin laptops 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 SSD type in the documentation for your computer.

External SSD

Besides the internal ones, there is also external drives... They vary greatly in shape and size - choose the one that is most convenient for you.

As for the interface, they are connected to computers via the USB port. To achieve full compatibility, make sure that the port on the computer and the connector on the drive support the same uSB standard... The fastest data exchange rates are provided by the USB 3 and USB Type-C specifications.

2. Which memory is better: MLC or TLC

According to the number of bits of information that can be stored in one flash memory cell, 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 withstands fewer rewrite cycles, although the average user is unlikely to notice the difference.

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

The description of the drive can also indicate the type of mutual arrangement of memory cells: NAND or 3D V-NAND (or just V-NAND). The first type implies that the cells are located in one layer, the second - in several layers, which allows you to create an SSD of increased capacity. 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, affect the performance of an SSD. But these details are often not even mentioned in the description. Instead, endpoints of read and write speed appear, which are easier for the buyer to navigate. So, choosing between two SSDs, all other things being equal, take the drive whose declared speeds are higher.

Remember that the manufacturer only indicates 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 buy an SSD, a 64GB device is sufficient to make it a fast operating system. If you are going to install games on an SSD or store large files on it, then choose the volume that suits your needs.

But keep in mind that storage capacity greatly affects the cost.

Buyer's checklist

• If you need storage 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 run much faster than a conventional hard drive.
• If you are in the business or other tasks where high performance is critical, choose an M.2 SSD PCIe 3.0 x4 with MLC memory.
• Please carefully check the compatibility of the drive with your computer before purchasing. If in doubt, consult your dealer.

Solid state drives, or SSD (Solid State Drive) for short, are replacing magnetic hard drives. And although the abbreviation mentions the word drive - "disk", new storage devices can hardly be called disks, since they do not have anything resembling a disk.

Let's take a look at what solid-state drives (SSD) are good at and how they differ from all of us familiar hard magnetic drives - HDD.

Advantages of SSD over HDD.

The biggest advantage of SSDs over HDDs is that they speed much higher than "classic" hard drives. The fact is that SSDs use a completely different technology for recording, storing and reading information. The technology is borrowed from flash memory, so an SSD can be called a specialized high-capacity flash drive.

The second advantage of SSD is no moving parts and details. It's no secret that magnetic hard drives very sensitive to vibration loads, especially in working condition. Accidental fall and you can say goodbye to HDD forever. Also, it is not uncommon to get out of a standing drive that turns those same magnetic "pancakes". Mechanical parts are the Achilles' heel of any high-tech device.

Since SSDs simply do not have moving parts and parts, their resistance to vibration and shock is much higher than that of conventional HDDs.

The third and important quality of SSD for portable technology is their light weight... If you put a 2.5 ”SSD with a capacity of, for example, 128Gb on one palm, and a 2.5” HDD with 180Gb on the other palm, then the solid-state drive will seem to you just a "feather". They are incredibly lightweight.

The fourth advantage of SSDs over HDDs is that they consume less energy, and their working temperature is much lower.

These are, perhaps, all the qualitative differences between SSD and HDD.

SSD drive device.

This is what an average SSD looks like. Naturally, there are open-frame models on sale. The most common form factor SSDs are 2.5 ".

An ordinary solid-state drive is a printed circuit board with a set of microcircuits installed on it. This set consists of a microcircuit NAND controller and, in fact, microcircuits NAND memory.

The PCB area of \u200b\u200bthe solid state drive is fully utilized. Most of it is occupied by NAND memory chips.

As you can see, there are no mechanical parts or disks in an SSD drive - only microcircuits. It is not for nothing that recently SSDs are increasingly called "electronic" disks.

Types of memory in SSD.

Now that we have dealt with the device of SSD-drives, let's talk about them in more detail. As already mentioned, an ordinary SSD consists of two interconnected parts: memory and controller.

Let's start with memory.

The SSD uses NAND memory to store information, which consists of a huge number of floating gate MOSFETs. They are also called cells (memory). The cells are combined into pages of 4 KB (4096 bytes), then into blocks of 128 pages, and then into an array of 1024 blocks. One array is 512 MB and is controlled by a separate controller. Such a multi-level model of a storage device imposes certain restrictions on its operation. So, for example, you can erase information only in blocks of 512 kB, and writing is possible only in 4 kB. All this leads to the fact that a special controller manages the recording and reading of information from memory microcircuits.

It is worth noting here that a lot depends on the type of controller: read and write speed, fault tolerance, reliability. We will talk about which controllers are used in SSDs a little later.

There are three main types of NAND memory used in SSDs: SLC, MLC, and TLC. In memory type SLC (Single-Level Cell), single-level transistors are used. This means that one transistor can store 0 or 1. In one word, such a transistor can only store 1 bit of information. It won't be enough, won't it?

Here the big-headed men "scratched their turnips" and figured out how to make a transistor-cell 4-level. Moreover, each level represents 2 bits of information. That is, on one transistor, you can write one of four combinations of 0 and 1, namely: 00 , 01 , 10 , 11 ... That is, 4 combinations, against 2 for SLC. Twice as many as on SLC cells! And they called them multi-level cells - MLC (Multi-Level Cell).

Thus, on the same number of transistors (cells), it is possible to write 2 times more information than if SLC cells were used. This significantly reduces the cost of the final product.

But MLC cells have significant disadvantages. These cells have a shorter lifespan than the SLC, averaging 100,000 cycles. For SLC cells, this parameter is 1,000,000 cycles. It is also worth noting that the read and write times for MLC cells are longer, which reduces the speed of the solid-state drive.

Since the technologies for storing information on solid-state media are developing very quickly, then, perhaps, everything that you learned about here is already considered obsolete.

For example, when this article was still being written, MLC-based SSDs were in the lead. But, now they are practically supplanted by SSD-drives with memory like TLC - three-level cells ( Triple-level cell). TLC memory has 8 levels, and, therefore, each cell can store already 3 bits of information (000, 001, 011, 111, 110, 100, 101, 010).

Flash memory comparison table: SLC, MLC and TLC.

The table shows that the more levels are used in a cell, the slower the memory based on it works. TLC memory is clearly inferior both in speed and in "lifetime" - rewriting cycles.

By the way, TLC memory has long been used in USB flash drives, which, although it "wears out" faster, is much cheaper. That is why the cost of USB flash drives and memory cards is steadily decreasing.

Despite the fact that SSDs are manufactured by various companies under their own brands, many people buy NAND memory from a small number of its manufacturers.

NAND memory manufacturers:

Intel / Micron;

• Toshiba / SanDisk;

  Samsung.

Thus, we learned that SSD drives come in three different types of memory: SLC, MLC, and TLC. SLC-based memory is faster and more durable, but expensive. Memory on MLC cells is noticeably cheaper, but has a lower resource and speed. Only SSD-drives based on MLC and TLC flash memory can be found on wide sale (at the time of editing the article). Disks with SLC memory are almost never found.

3D XPoint memory and Intel Optane storage.

It is also worth noting that recently, drives have appeared on sale that are based on a new type of non-volatile memory. 3D XPoint (read as "three di cross point"). Based on 3D XPoint, Intel Corporation manufactures solid state drives under the Intel Optane brand. The development of a new type of memory was carried out by two companies Intel and Micron.

3D XPoint is a fundamentally new type of non-volatile memory, in contrast to NAND memory, which has been around since 1989.

3D XPoint has a higher read-write speed, since the cell is accessed directly. The 3D XPoint is said to have no transistors at all, and each cell is capable of storing 1 bit of information. Direct access eliminates the need for complex controllers that are required in NAND drives with multi-level transistors (MLC, TLC). In addition, the resource (wear resistance) of this memory is much higher than that of NAND, which has such a basic defect as the leakage of electrons from the cells.

Since the speed of Intel Optane drives exceeds the capabilities of the SATA interface, they are usually manufactured in form factors M.2, as well as in the form of a solid-state drive for a PCI Express slot (PCI-E AIC ( add-in-card)). A new interface is used to work with such drives NVMewhich is replacing SATA.

SSD controllers.

At the time of this writing, the following controllers are most common:

About installing Windows on an SSD.

It is not recommended to install Windows XP on an SSD, as this operating system is not designed to work with an SSD. In Windows 7, 8 and 10, SSD support is fully present. However, for a more durable and "correct" operation of the SSD with Windows 7, it is recommended to check / configure some parameters of this OS.

Today we will discuss with you the main points and principles of the operation of solid-state SSD technology. As you remember, we conducted a comparative test of one SSD and two HDD disks. We considered how it looks from the inside and what basic blocks it consists of.

Also - we have listed the main advantages of this technology, and now we will consider the disadvantages that are inherent in it at the moment. Let's present the main ones in the form of a list:

1. High (in relation to HDD disks) cost of data storage, i.e. - we get smaller disk capacity for a lot of money
2. High vulnerability (relative to devices with magnetic recording principle) to electrical interference and power supply problems (sudden power outages, magnetic fields, static electricity)
3. It is impossible to completely fill the disk (15-20% of the space should be free)
4. The service life of a medium is limited to a certain number of write cycles of its cells

But let's go in order! Let's start with what is an SSD drive and how does it work?

It is a solid state drive that uses NAND flash memory chips instead of traditional plates covered with a ferromagnetic layer.

NAND memory is the evolution of flash memory, the chips of which were much slower in speed, durability and structurally looked more massive.

You may be wondering that flash memory was developed in one of the divisions of Toshiba in 1984. The very first commercial chip based on this development was released by Intel in 1988. A year later (in 1989) the same "Toshiba" introduced a new type of flash memory - NAND.

At the moment, there are three main options (modifications) of NAND memory:

• SLC (Single Level Cell)
• MLC (two-level - Multi Level Cell)
• TLC (three-level - Three Level Cell)

The most expensive and reliable solutions are devices based on SLC chips. Why? They allow to store only one bit of information in each memory cell. In contrast, MLC and TLC chips can store two and three bits, respectively. This is made possible by using different levels electric charge on the gates of memory cells.

It can be schematically depicted like this:

Such a multi-level structure makes it possible to dramatically increase the capacity of chips with the same physical volume (as a result, each gigabyte is cheaper). BUT! Nothing is given for free! Therefore, MLC and TLC chips have a drastically reduced life span, which is directly related to the number of rewriting cycles of their cells.

For SLC, this is 100,000 erase / write cycles, for MLC - 10,000, and for TLC - only 5,000. This decrease in reliability is associated with the gradual destruction of the dielectric layer of the floating gate of the cell due to the small reserve of changing its state under the influence of electric current. Plus, due to the fact that with each new level the task of error-free recognition of the electrical signal level becomes more complicated, which means that the total search time for the desired cell with data increases, the probability of reading errors increases.

To combat the phenomena described above, manufacturers have to develop specialized highly intelligent control microcontrollers for SSD disks, which, in addition to I / O procedures, must write information to the medium so that the chips of its flash memory wear out evenly and control this wear by balancing the load, as well - carry out error correction, etc.

It is the controller that is the weak point, since it is more sensitive to power problems and damage to the firmware (firmware) in it can lead to a complete loss of all user data. And their correct restoration is even more labor-intensive operation than in the case of HDD disks. Due to the fact that the data is scattered across different memory chips and it is necessary to correctly restore their original structure, and this is not easy.

Therefore, manufacturers of SSD drives regularly update the firmware of their drives and post them for free download, modifying and improving the algorithms of the device and preventing data loss in case of an emergency.

Manufacturers are also struggling with the wear of MLC memory cells by a method that has proven itself in disks with a magnetic recording principle: reserving a part of their volume (10-20%) to dynamically replace worn-out cells. In the case of HDD, this area is for replacement.

But we, as users, can help our SSD drive idle not to waste its limited "life" resource and configure the operating system in such a way as to minimize unnecessary disk accesses.

I'll show you the general principles of what to do and what to try to avoid, and you yourself will tune your system for optimal performance with a solid state drive.

For example: we know that the Windows operating system actively uses the paging file (hidden system file "Pagefile.sys"). What does this mean in relation to the wear and tear of the cells of the SSD drive and all that we talked about above? And the fact that a separate area of \u200b\u200bthe system flash disk is heavily used (often overwritten by some kind of service data that we do not need and, in fact, is actively wearing out)!

What can be done? Correctly! Move the paging file to another (not SSD) disk, as I did, or, with a large amount of RAM, refuse it altogether (set it to "0")?

Going further: defragmentation is not only unnecessary this type devices (their access speed is the same for any cell, regardless of where the final file is located), but it is also simply harmful. For the same reason as described above. Excess (idle) disk accesses only further reduce its limited resource. This means we turn off the corresponding defragmentation service. Also, it will not be superfluous to disable file indexing, which is needed for faster searches, but do we use it so often?

The principle, I think you get it. And now I would like to show you a small program "SSD Mini Tweaker" (tweaker - optimizer), which in a similar way optimizes the operation of an SSD drive. It is enough to put down the necessary checkboxes in front of the corresponding items and click the "Apply changes" button.

The computer will restart and the changes will take effect. The program is remarkable in that it has a Russian interface and detailed help in Russian. So, at any time you can familiarize yourself in detail with the function that you are going to disable or leave enabled.

You can download the utility. The archive contains versions for 32 and 64-bit systems and a help file in Russian.

Since we have spent so much time on the issue of optimal disk utilization and wear and tear of its memory cells, I cannot but present you another interesting development. The program "SSD Life Pro", the main task of which is to keep track of the operating time of the disk and report the approximate date of its failure.

What do we see here? Record "FW: 1.00" is the firmware version of the disk, below shows the occupied and free space on it, the total operating time from the first start and the number of starts. Also pay attention to the TRIM line (must be active), this indicates that the performance of the SSD disk will be optimal.

Below is a screenshot of the operation of the same program, but taken from the website of its developer. It shows that the Intel disk has correctly passed its SMART parameters to the utility and based on them the utility displayed an extended forecast of its state.

As you can see, the failure of the drive is "scheduled" for November 7, 2020 :)

If we click on the link “What do you think?” At the top of the program window, then we will go to the developer's website and will be able to familiarize ourselves (in Russian), how exactly such a calculation is performed?

You can program. If it accurately shows the "lifetime" of your disk - unsubscribe, I think all readers will be interested!

At the end of this topic, let's listen to the recommendation of the respected Intel firm, which says that the ideal operating conditions for a solid state drive SSD is less than 75% data filling with the ratio of static (rarely changed) and dynamic (frequently changed) information - 3 to 1 ... Do not use the last 10-20% of the disk space, as they are needed for the correct operation of the "TRIM" command. To work she needs free space to regroup data (same as defragmentation function). General rule such - the more free space - the faster the device works.

At the moment, an SSD drive is ideal as a system partition on which the operating system and programs are installed and that's it. The data and all work on them should (if possible) take place on the second (HDD) disk. Also, solid-state drives can be effectively used on servers to cache static data.

For now, let's take a quick look at why the more expensive SSD solid-state drives have such excellent speed qualities and how else are they different from their "younger" counterparts?

Firstly: this is the same intelligent drive controller chip, which can be designed as a multi-channel, i.e. - can write data simultaneously to each flash memory chip of the disk. As a result, the overall performance of the device will be equal to the speed of one memory chip multiplied by the number of controller channels. Well, this is to simplify things a little :)

Also in more expensive models, additional elements are used that are soldered onto the board. This can be, for example, a series of capacitors located near the memory chip of the disk, which ensure the guaranteed retention of data from the cache memory in the event of a power failure.

When a critical mass of bad drive cells is reached, a well-executed chip firmware can completely block the SSD disk for write functions and put it into read-only mode, which guarantees the safety of user data (possibility) until the device is completely out of order.

And at the end of our article, let's touch on another interesting type of solid state drives. These are "RAM SSD" drives. What is it?

Such hybrid devices use volatile chips to store information, which are completely identical to those used in the modules. They have ultra-fast data access, read and write speeds and can be used to speed up large databases and where peak performance is needed.

Such systems are equipped with batteries to maintain functioning in the absence of power, and more expensive models are equipped with backup systems, when data is copied to HDD media.

This is what such a device might look like, which is identified by the operating system as a hard drive.

And here is a simpler version, made in the form of a PCI Express X1 card

As you can see, the principle of operation here is the same, but the function of flash memory chips or HDD "pancakes" here is performed by ordinary RAM modules.

Now, as promised, I want to say a few words about the subjective feelings after using the solid state drive. The operating system (Windows 7) boots and shuts down significantly faster. The same can be said about installing and running programs. Some applications are simply surprising: "Microsoft Word 2003" "fires" in less than a second! You do not have time to mentally prepare yourself to work with him :) Yes, quickly, but do not expect something phenomenal, after all, this is not a "revolution", but an "evolution" :)

That's all for today. See you in the next articles!

And at the very end - what the production of NAND memory chips looks like: