Classification of SSDs

Classification method:

There are two kinds of storage media for solid state disk, one is flash memory (flash chip) as storage media, and the other is dram as storage media. The latest is Intel’s xpoint granular technology.
Flash based SSD:
Flash based solid state disk (ideflash disk, serial ATA flash disk): flash chip is used as storage medium, which is also commonly referred to as SSD. Its appearance can be made into a variety of shapes, such as notebook hard disk, micro hard disk, memory card, U disk and so on. The biggest advantage of this SSD is that it can be moved, and the data protection is not controlled by the power supply. It can adapt to various environments and is suitable for individual users. Long life, depending on different flash media. SLC flash memory generally reaches tens of thousands of times of PE, MLC can reach more than 3000 times, TLC can also reach about 1000 times, and the latest QLC can also ensure the service life of 300 times. The annual writing capacity of ordinary users does not exceed 50 times the total size of the hard disk. Even the cheapest QLC flash memory can provide a writing life of 6 years. High reliability, high-quality household solid-state disk can easily reach one tenth of the failure rate of ordinary household mechanical hard disk.

Based on DRAM class:
DRAM based solid state disk: DRAM is used as the storage medium, which has a narrow application range. It imitates the design of traditional hard disk, can be set and managed by file system tools of most operating systems, and provides industry standard PCI and FC interfaces for connecting hosts or servers. The application mode can be divided into SSD hard disk and SSD hard disk array. It is a kind of high-performance memory, which can be written indefinitely in theory. The drawback is that it needs an independent power supply to protect data security. DRAM solid state drives are relatively non mainstream devices. [1]
Based on 3D xpoint class
Solid state disk based on 3D xpoint: it is similar to DRAM in principle, but it belongs to nonvolatile storage. The read delay is extremely low, which can easily reach 1% of the existing solid-state disk, and has nearly unlimited storage life. The disadvantage is that the density is relatively low compared with NAND, and the cost is very high. It is mostly used for fever level desktop computers and data centers.

DRAM based solid state disk: DRAM is used as the storage medium, which has a narrow application range. It imitates the design of traditional hard disk, can be set and managed by file system tools of most operating systems, and provides industry standard PCI and FC interfaces for connecting hosts or servers. The application mode can be divided into SSD hard disk and SSD hard disk array. It is a kind of high-performance memory, which can be written indefinitely in theory. The drawback is that it needs an independent power supply to protect data security. DRAM solid state drives are relatively non mainstream devices.  [1] 

Based on 3D xpoint class

Solid state disk based on 3D xpoint: it is similar to DRAM in principle, but it belongs to nonvolatile storage. The read delay is extremely low, which can easily reach 1% of the existing solid-state disk, and has nearly unlimited storage life. The disadvantage is that the density is relatively low compared with NAND, and the cost is very high. It is mostly used for fever level desktop computers and data centers.and the cost is very high. It is mostly used for fever level desktop computers and data centers.