What are solid state drives. Solid state hard drive SSD. From disks to SSDs

Today, most users' computers are equipped with HDDs. This is a popular type that has its advantages, but SSDs are gradually replacing it from the market. Almost any modern laptop or desktop computer is sold with such storage inside, but most buyers do not quite understand what an SSD is. Let's figure it out and define what this hard drive is, what pluses and minuses it has over classic and already obsolete HDD drives.

What is SSD?

If we talk in simple words then it is a computer memory device that consists of a microcontroller and microcircuits. This abbreviation stands for Solid State Drive (or Solid State Disc), which translated from English means "solid state drive".

Note that this is a non-mechanical device. Unlike standard HDDs, SSDs have no moving mechanical parts: a spindle, a reading head. Therefore, when this device is operating, nothing moves inside, does not rotate at great speed, and does not make noise. Therefore, nothing wears out here. All of these parameters are extremely important, since they are the ones that distinguish the two technologies. The old HDD models were too sensitive to all kinds of vibrations, the new ones were not.

So, a hard disk drive stores all information not in sectors on hard platters, but directly in memory chips. A special controller allows you to write data into cells and receive them from there, transferring them to the PC interface. In fact, an SSD is a large flash drive with a huge amount of memory, but its performance or bandwidth is much higher than not only the performance of a simple flash drive, but outdated HDD drives.

What is it for at all?

More efficient and efficient replacement of outdated HDD drives - this is the main goal pursued by the developers of these digital media. They are smaller, work very quickly and do not make noise during operation. On a computer that uses an SSD drive, the operating system boots up much faster, and in general, performance in different programs increases.

As for a laptop, where every watt of power counts, the installation of an SSD is more than justified. Here, it consumes a little power, which allows laptop manufacturers to provide a higher autonomy of models. In addition, due to the small size of these devices and less heating, you can create more compact laptops and not bother too much about the implementation of the cooling system. hard disk.

Structure

Outwardly, the SSD looks trite: it is a small green board with microcircuits and a controller on it, which is placed in a plastic or metal case. On one side of the case is a SATA connector through which the drive is connected to the computer's motherboard. Nearby is the power connector. Everything is just like in a regular HDD.

So, the memory chips located on the board are information storages. Unlike outdated hard disks used in HDD models, reading information from such media is much faster. Hence, GPUs get the required information for processing from the hard disk faster, which speeds up the operation of the entire system.

Controller

The on-board controller is an analogue of a processor, only it is highly specialized. Its main task is the distribution of information in microcircuits. It can also perform various service tasks: cleaning memory, redistributing cells, etc. All service tasks must be performed in a timely manner, otherwise failure to do so may lead to loss of information.

Also, the composition of the storage media for laptops and stationary PCs includes buffer memory for caching data. It is a high-speed random access memory where data is first routed, then modified and written to disk.

Installation

Most users initially know how to install the SSD. This procedure is completely the same as installing a conventional HDD.

Unable to install this disc wrong. You just need to insert it into the case, screw the assembly with screws and connect the SATA cable to the motherboard and to the media connector. The cable from the power supply is inserted into the adjacent connector. There are no cables with connectors in the system that could be mistakenly connected to the device, so there should be no problems with installation.

How it works?

It is rather difficult to explain how this device works. It is based on the specifics of the functioning of certain memory cells. Here, data processing is carried out not by bytes, but by blocks. Moreover, each cell has a certain resource of write cycles, and the more often data is written and deleted from memory, the sooner the disk will exhaust its resource and fail.

Reading data is fast. All operations are carried out through the controller, which "understands" the desired block address and accesses the required memory cell. There are times when it is necessary to read several inconsistent blocks at once, but this does not affect performance. There was no such advantage in HDD media.

The process of recording information is carried out in the following sequence:

  1. Reading a block into the cache.
  2. Changing information in the cache memory.
  3. Erasing a block in memory.
  4. Writing a new block to memory at an address that has been pre-calculated by a special algorithm.

Recording involves accessing memory cells on digital media SSD. Before writing, the block is cleared, and in order for the disk to wear out sequentially, the controller calculates the block numbers using special algorithms.

Note that the erasure of blocks is carried out during idle operation of the medium. This shortens the time it takes to write to the disc. In this case, user intervention is not required, the system automatically executes the command to clear the blocks.

Types of SSD media

There are several types of these devices. They are divided according to the type of interface used to connect to a PC:

  1. SATA. SATA drives are the most common. The same connector is used to connect conventional HDDs. There is also a smaller version of this connector - mSATA.
  2. PCI-Express. These connectors usually connect video cards, but you can also connect a disk with the corresponding connector. This interface is located on the motherboard. When a disk is connected via PCI-Express, its performance will increase due to the higher bandwidth this interface. Typically, SSD media for servers are connected this way.
  3. M.2 is another miniature option for connecting drives.

Characteristics

So, you now understand what STO is. It remains only to mention the main characteristics of these devices:

  1. Capacity. One of the important parameters, which is most often indicated by a non-multiple power of two. If the capacity HDD drives was 256 or 512 GB, then the capacity of SSD devices is usually 240 or 480 GB, respectively. This is done due to the reservation of a part of the memory by the controller, which is necessary to replace the blocks that have exhausted their resource. The user does not see the replacement of blocks, and he will not lose data. That is, if the specifications indicate the volume of 480 or 500 GB, then in fact 512 GB is available there. It's just that different controllers reserve a certain amount.
  2. Speed. Most devices have speeds of 450-550 Mb / s. This speed is equal to the bandwidth SATA interface through which the drive is connected to the motherboard. However, this is quite enough for any task. After all, even the write speed in applications is lower. In the characteristics, the write speed is most often indicated, and not the bandwidth.
  3. The number of microcircuits. The more memory chips there are, the more operations can be processed in one unit of time. That is, the number of chips determines the performance. Typically, the write speed is faster for models with more memory. This is due to the fact that as the amount of memory grows, so does the number of chips.
  4. Memory type. The cheapest SSDs have TLC memory, the expensive ones have MLC memory. Samsung is using and improving its own 3D-NAND memory. The differences in the type of memory used are not visible in practice.

Conclusion

Despite the fact that such digital storage of information vaguely resembles a modern large USB flash drive, there are differences between them. In particular, these discs have a wide range of realized modern technologies, due to which a large increase in performance is achieved without loss of reliability. The speed of the entire system increases significantly when replacing the old hard drive with a new solid-state one. Now we have finally figured out what an STS is and what are its features.

Hi friends! As they said in Russia: "Every merchant praises his goods" and no matter how much you read various articles about solid-state drives SSD, you will hardly meet the same opinion. Someone read something and decided to buy a Samsung solid-state drive, who is Toshiba, while others decided at all costs to purchase an OCZ Vertex SSD or Kingston.

About a year and a half ago, my friends and I firmly decided to buy an SSD for a solid-state drive, we all have them, but we do not. My comrades asked me to test various SSDs and choose the best one.

Solid-state drives are not bought very well, so sellers of computer goods do not carry a lot of them, so that they do not lie dead in the warehouse. So we also do the same, so at my disposal were the leaders in SSD sales at that time. The most inexpensive of the whole company turned out to be the Silicon Power V70 SSD, which I left the test for later.

In my tests, I was not particularly sophisticated, I installed an operating system on each SSD, then compared the SSD and a regular HDD in the CrystalDiskMark and AS SSD Benchmark test programs. I didn't have to prove that SSD is better than a regular HDD. Windows installed on a solid state drive SSD loaded in 4 seconds, test programs CrystalDiskMark and AS SSD Benchmark showed complete superiority of SSD over conventional HDD by 3-4 and even 5 times.

I performed all the tests on the trading floor and the information was available to buyers, in short, all test SSDs were disassembled, besides that day was good for sales and even there was not a single SSD left in the shop window, well, I think I was left without a solid-state drive! And then I remembered about SSD Silicon Power - V70. Basically, I knew this good manufacturer from Taiwan, but I still wanted something different, for example Crucial or Plextor!

I decided to test it too at the end of the working day and after the tests I was a little surprised, the V70 turned out to be a notable solid-state drive in no way inferior to other SSDs I tested and sold during the day. And the SiSoftware Sandra program generally awarded him the first place.

During the year, where it just did not work for me: on a laptop and on various stationary system units and instead of a flash drive, I carried it in my pocket and dropped it on the floor, but nothing, it still works fine.

Well, okay, enough chatter, I'll move on to the main thing in the article, the answers to your questions about the solid-state drive and at the end of the article I will give some tests proving that the SSD for installing the operating system is what the doctor ordered.

ALL your questions regarding solid state drives SSD.

1. What is the internal structure of an SSD? Should I buy an SSD based on which NAND flash: SLC, MLC or TLC?

2. Which SSD manufacturer should I prefer?

3. Is the lifespan of an SSD really very limited? After how many years of use will my SSD fail?

4. Does the user threaten to lose all recorded data in case of exceeding the resource of memory chips?

5. Is it worth it, to extend the life of the SSD, disable hibernation, paging file, recovery, disk indexing service, disk defragmentation, Prefetch technology, transfer cache browser and directory of temporary files to another HDD etc?

6. How much faster is an SSD than a conventional hard drive?

Comparing different SSD performance

It is important to know not only the average sequential read and write speed on an SSD, but also the speed of random writing in blocks of 512 kb and 4 kb, which is hushed up by all SSD manufacturers! Disk activity for most users occurs mainly in such areas!

When comparing SSDs from different manufacturers in the AS SSD Benchmark program, we can see the following result, for example:

My Silicon Power V70 SSD showed:

431MB / s read / write sequential, 124MB / s write

Speed ​​in reading and writing in 4 KB blocks, it turned out 16MB / s read, 61MB / s write

SSD from another manufacturer... As you can see, the high (higher than my SSD) sequential read and write speed is 484 MB / s (read), 299 MB / s (write), but there is a drawdown in reading / writing in 4 KB blocks, namely 17MB / s read, 53MB / s write.This means this SSD is not faster than mine., although the box of this SSD may show off 500 MB / s numbers.

SiSoftware Sandra SSD Test

My SSD was ranked # 1 among similar models

In our time, it is difficult to imagine a person who would not have a computer. New devices and gadgets appear every year. The same applies to information storage devices. Recently, SSD media have appeared on the market, which are gradually replacing HDD disks.

Many users are interested in the question, what are the advantages of an SSD drive and is it really as good as the manufacturer says about it? To answer this difficult question you need to figure out what is similar device.

What is an SSD drive?

So what is an SSD drive? If you decipher this abbreviation, then you get a solid-state drive, which means a solid-state storage medium or non-mechanical storage device developed on the basis of microcircuits. Such a drive, by the principle of data recording, resembles a USB flash drive.

Solid state drives do not have a magnetic disk. All data is written to the microcircuit. Therefore, when the disc is working, it is completely inaudible. In addition, a conventional hard drive is several times slower than an SSD.

The first analogs of a solid-state disk were media that were produced on the basis of RAM memory. To prevent the transferred data from disappearing, special batteries were connected to them. Modern SSD drives are manufactured using a completely different technology.

"Filling" SSD

As noted earlier, solid state media does not use a magnetic disk. The main parts of such a device include:

  • Controller;
  • Flash memory;
  • Connection interface;
  • Housing.

It is important to note that solid-state disks may differ from each other. Therefore, before buying a solid-state drive, it is recommended that you study the "stuffing" of the drive in more detail.

Controller

The controller refers to the processor that controls the read and write procedure. It is one of the most important elements of a solid state drive.

The tasks of the controller include:

  • Uniform distribution of downloaded files throughout the disk;
  • Monitoring the state of memory cells;
  • Blocking of cells, in case of their wear;
  • Compact file packaging for increased productivity.

SSD speed directly depends on the controller. Therefore, when choosing a disk, you need to pay attention to the controller. Developers from Intel, Marvel, SandForce and Indilinx are popular among users.

Flash memory

Modern solid state drives can contain one of three types of memory, namely:

TLC memory allows writing 3 bits simultaneously in one cell. In this case, it is possible to perform 1000 rewrites. This type of memory is the cheapest, so it has been used for several years in the development of flash drives. Thanks to this technology, the cost of solid-state drives has become lower.

This type of memory, such as MLC, allows you to write 2 bits in one cell. As for the rewrite cycles, they are equal to 3000. In most cases, this type of memory is used to create SSD drives. It should be noted that compared to TLC memory, MLC is more expensive.

SLC memory facilitates writing 1 bit to 1 cell. In this case, the maximum number of rewriting cycles is 100,000. Of course, the presence of such a number of cycles will appeal to everyone, but the cost of such "pleasure" is too high.

Connection interface

Most often there are drives that support the SATA3 interface. There are also several more options:

  • External SSD drive;
  • PSI card that plugs directly into the motherboard connector;
  • A drive with an mSATA interface, which is located in laptops or netbooks.

It is important to note that the SATA3 interface is compatible with the 1st and 2nd generation interfaces. This will change the data transfer rate. It is noteworthy that on laptops, a solid state drive is installed instead of a DVD-ROM, which is practically not used by modern users. In this case, the operating system must be installed on the SSD. The rest of the hard ones will be used as storage.

Housing

An ordinary hard drive is 3.5 inches in size. As for the solid state drive, they come in a 2.5-inch form factor. If a solid-state drive will be installed instead of a hard drive, you will have to use a special adapter. A similar device is a small shelf made of metal. It is attached to the place where the disk is installed.

Due to its small size, the solid-state drive can be installed both in a stationary computer and in a laptop. It should be noted that there are also hybrid drives that use USB interface... Most often, the form factor is 3.5 inches.

Benefits

Solid state drives have a number of advantages that you should look out for. The main advantage is the speed of writing and reading data. Compared to conventional hard drives, these figures are several times higher. The high speed of the drive improves the performance of the operating system. This is especially noticeable at the time of loading the OS. On devices with HDD, loading is carried out within 40 seconds, as for solid-state media, then the load takes no more than 7 seconds.

Another advantage can be considered high resistance to the effects of various external factors. This is due to the fact that an SSD does not have a fragile mechanism compared to a conventional hard drive. Such drives cope perfectly with temperature changes, and also withstand vibration and light shocks to the case.

The lack of noise and low energy consumption is considered an important advantage. At the same time, the drive does not need special cooling, compared to hard drives. Thanks to the characteristics of the SSD, it is a worthy replacement for an HDD.

disadvantages

Despite their speed, quietness, and low power consumption, SSDs have several significant drawbacks. The main disadvantage can be considered high cost. Such drives are several times more expensive than HDDs. This is due to the complexity of manufacturing controllers and memory chips. Do not be upset, as technologies are developing exponentially, which means that the cost will gradually be reduced.

Unfortunately, the high cost is not the only significant drawback. Solid state drives have a maximum capacity of 1 TB. As for hard drives, their capacity has already reached 8 TB. As you can see from the numbers, the differences are tangible.

Be prepared for the fact that SSDs don't last forever. When a certain number of overwrites are made, the memory will start to fail. Of course, this does not mean that the device will last only 1 month. It must be remembered that someday the device will cease to function, and it will be impossible to retrieve information.

Another disadvantage is power surges. SSD drives fail after several hops. There is a high probability that the drive will simply burn out when the voltage drops. As for the hard drive, in such a situation, only a certain sector fails, and most of the information can be restored.

Choosing a storage medium

Before heading to the store for a brand new SSD device, it is recommended that you pay attention to a few recommendations, thanks to which it will be easier to make your choice. You don't need to buy the most expensive disk, because the SSD is designed only to work with the operating system and to install additional software. As for the storage of information, you need to use an additional hard disk.

To increase the system performance, it is enough to purchase a 60-120 Gb solid-state drive. In this case, it is necessary to calculate the volume based on the fact that the disk will not be completely clogged with information. If such a situation occurs, performance will drop dramatically, and it will be impossible to restore it.

It is recommended that you review your computer configuration before purchasing a device. This is to make sure that motherboard able to work with high-speed storage media. Otherwise, there is simply no point in purchasing such a device.

How to properly handle solid state media

As noted earlier, SSD drives are short-lived, so it is necessary to extend the lifespan whenever possible. To do this, it is enough to follow a few simple rules:

  • Only an operating system that recognizes the TRIM command can be installed on solid-state media. These operating systems include Windows 7 and higher, as well as Linux starting from version 2.6.33 and MacOS6.6;
  • Never completely fill the disc. Otherwise, the speed of reading and writing will be reduced several times. In this case, it will be impossible to restore it, even after cleaning the disk;
  • No need to use a swap file. Best to add some more random access memory;
  • All personal files (documents, photos, videos) should be stored on your hard drive. If you are using a netbook, then this data must be copied to a separate SD card.

If you follow these simple instructions, the life of the disk will increase significantly.

Video review 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 speed.

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 an SSD drive is needed. 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 the insignificant 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 more capacious and 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 doesn't 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. For data recording, 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 make 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, due to a blow to the case, contact between the components may be broken, 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 that drives 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 important 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, there is a delay caused by the need to move the read head. Because of this, the speed of work is significantly reduced. The similar latency when 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 malfunction of the 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 an SSD drive in a 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

When 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 supply circuits minimizes the risk of irreparable failure of the drive in the event of a power supply failure, and the amount of memory in a laptop is not as important as in a desktop PC.

As for the smaller resource of work, experience service centers shows: a laptop hard drive fails and undergoes premature wear several times more often and faster than in a stationary 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 the 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 is 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 main this moment, some of the SSD buyers. Using a solid state drive allows them to get better performance in 3D games by reducing their startup 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 what to supply data SSD processor will allow much faster and more efficient than railway.

For gamers high price a 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 do 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 multimedia computer unnecessarily. 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 storage (for Windows installations) will not be superfluous. It will significantly increase the overall performance of the PC, reduce the noise level of the system unit and more economically consume electricity.

A big fan of high-quality Chinese technology, a lover of clear screens. Supporter of healthy competition between manufacturers. Keeps track of news in the world of smartphones, processors, video cards and other hardware.

Today we will discuss with you the main points and principles of functioning of the technology of solid-state SSD disks. As you remember, we spent comparative testing 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 (relative to HDD disks) cost of data storage, i.e. - we get a smaller disk capacity for a lot of money
  2. High vulnerability (relative to devices with magnetic recording principle) to electrical noise 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?

This 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 Toshiba divisions in 1984. The first commercial chip based on this development was released by Intel in 1988. And 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. Unlike them, 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 a small reserve of changing its state under the influence of an 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 over 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 with a method that has proven itself in disks with a magnetic recording principle: by reserving a part of their volume (10-20%) for dynamic replacement of 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 will show general principles what to do and what to try to avoid, and you yourself will configure your system to optimal performance with 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 ​​the 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? Right! 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. Extra (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 more quick search, but how often do we use it?

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 the 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-bit and 64-bit systems and a help file in Russian.

Since we have devoted so much time to 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 you can see 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?" In the upper part of the program window, then we will go to the developer's site and we will be able to familiarize ourselves (in Russian), how exactly such a calculation is performed?

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

At the end of this topic, let us heed the recommendation of the respected company "Intel", which says that the ideal operating conditions for an SSD of a solid-state drive is its fullness of data by less than 75% 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, it needs free space to regroup the data (just like for the defragmentation function). General rule such - the more free space - the faster the device works.

At the moment, an SSD drive is ideal for the role 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 for caching static data.

Now, let's take a quick look at why more expensive models 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 chip of the drive controller, which can be designed as a multi-channel, i.e. - can write data simultaneously to each flash memory chip of the disk. Eventually - overall performance 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 that data from the cache memory is guaranteed to be saved 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 offer 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 operation 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 I promised, I want to say a few words about the subjective feelings after using the solid state drive. Operating system(Windows 7) boots and shuts down noticeably faster. The same can be said about installing and running programs. Some applications are simply surprising: “ Microsoft Word 2003 "shoots" 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: