The choice of a solid state drive should be based on factors that are really significant to the user - the purpose, the interface used, the type of flash memory.

The fact is that manufacturers offer, in terms of the nature of use, two main types of SSD drives - consumer and server . The latter are designed to work under high and continuous load, so they sometimes have special eMLC memory installed, which has high wear resistance and a resource that is several times greater than that of a consumer disk. In addition, server SDDs use technologies that increase their fault tolerance in case of force majeure, for example, during power outages. Server drives can certainly be used in personal PCs, but they cost many times more than consumer models, and in some cases the game is simply not worth the candle.

Another important difference between SSDs is the interface to connect to the system.

The most common SSDs (the vast majority) have a SATA interface . This is the same serial interface that is used for classic hard drives. Most SATA SSDs even look like HDDs - these are 2.5-inch cases with a height of 7 or 9 mm. They can be easily installed in a computer instead of an old hard drive, or even used with a 3.5-inch one. Modern versions of SATA are designed for increased data transfer rates. Today it is 6 Gb / s. This is more than enough for the mass consumer, but manufacturers of powerful and server solutions try not to use the SATA interface.

For compact mobile devices, there is the mSATA form factor . Drives of this format are a small card with soldered microcircuits and are installed in special slots of some devices. The main advantage of mSATA is its miniaturization, in all other respects these are the same SATA SSDs. Experts recommend purchasing such drives only to upgrade those devices in which the mSATA connector is provided initially. See here qualcomm pc at Apcsilmic.

If SATA bandwidth is not enough, you can use a PCI Express SSD . Depending on the protocol version and the number of data lanes, PCI-E bandwidth can be up to five times that of SATA. Such disks use the most productive technologies, therefore, in terms of cost, they fall into the highest price category. Typically, PCI SSDs come in the form of expansion cards installed in slots (connectors), and they are only suitable for personal desktops. Recently, NVMe drives have become very popular., further increasing the speed and efficiency of the system. However, such solutions are compatible only with the latest platforms and can only work in the latest versions of operating systems.

An intermediate option between inexpensive, but "relatively slow" SATA and fast, but expensive PCI-E are M.2 form factor drives . Perhaps it is SSD M.2 that will become the new generally accepted standard. However, this is not yet another new interface, but only a specification of the size of the disk and the connector required to install it. The M.2 drive works on one of the mentioned interfaces - SATA or PCI-E. An M.2 drive is a small board with elements soldered to it, and most motherboards today have the necessary slots. If you need to upgrade your gaming PC or laptop, then you should pay attention to the M.2 SSD with PCI-E interface.

External SSDs are designed to be connected via USB 3.0 and USB 3.1 interfaces. Such models are rarely really efficient, but if you use a fast enough interface, they will work faster. The USB 3.0 interface is quite capable of providing data transfer rates up to 600 Mb/s.

The next important factor is the type of flash memory . The performance of the drive, its reliability and price depend on it. Consider what types of flash memory are (see Table 2 below).

SLC NAND stands for single-level cell, that is, each cell of such memory can store only one bit of information. The main problem of such a drive is its low capacity. But such a disk is more reliable, since the properties of the cell allow you to overwrite the information stored in it up to 100,000 times. The production of such microcircuits was more expensive, and consequently, the cost of disks also increased. Today it is quite difficult to find such models on the market, because in terms of price / capacity ratio they are much inferior to models based on MLC and TLC flash memory.

MLC NAND (multi-level cell) - a multi-level cell - the basis for most of today's solid state drives. Most disks use two-bit cells, and disk capacities vary from 8 GB to 1 TB. Disks are characterized by high speed and somewhat lower reliability. But the price for 1 GB of such a disk is constantly decreasing. Initially, models with 10,000 rewrite cycles were presented in drives with MLC memory, later the figure dropped to 3000 and 5000 cycles. For server drives, solutions based on MLC NAND are offered, and although in terms of the basic principle of operation, this is an analogue of MLC, the memory has increased resistance to frequent overwriting and can withstand a load three times more than conventional memory.