Classification of solid state drives

Classification

There are two types of storage media for solid-state drives, one is to use flash memory (FLASH chip) as the storage medium, and the other is to use DRAM as the storage medium. The latest is Intel's XPoint particle technology.

Flash-based SSDs

Flash-based solid-state drives (IDEFLASH DISK, Serial ATA Flash Disk): FLASH chips are used as storage media, which is also commonly referred to as SSD. Its appearance can be made into a variety of styles, such as: notebook hard disk, micro hard disk, memory card, U disk and other styles. The biggest advantage of this kind of SSD solid state drive is that it can be moved, and data protection is not controlled by power supply, it can adapt to various environments, and is suitable for individual users. Longer lifespan varies with different flash media. SLC flash memory generally reaches tens of thousands of times of PE, MLC can reach more than 3,000 times, and TLC can reach about 1,000 times. The latest QLC can also ensure 300 times of life, and the average user's one-year write volume does not exceed 50 times that of hard disks Overall size, even the cheapest QLC flash offers a 6-year write life. High reliability, high-quality home solid-state drives can easily reach one tenth of the failure rate of ordinary home mechanical hard drives.

DRAM-based

DRAM-based solid-state drives: DRAM is used as a storage medium and has a narrow range of applications. It imitates the design of traditional hard disks, and can be used for volume setting and management by file system tools of most operating systems, and provides industry-standard PCI and FC interfaces for connecting to a host or server. Application methods can be divided into two types: SSD hard disk and SSD hard disk array. It is a high-performance memory that can theoretically be written infinitely. The fly in the ointment is that it requires an independent power supply to protect data security. DRAM SSDs are relatively non-mainstream devices.

Based on the 3D XPoint class

Solid state drive based on 3D XPoint: In principle, it is close to DRAM, but it belongs to non-volatile storage. Read latency is extremely low, easily reaching one percent of existing SSDs, and has near-infinite storage life. The disadvantage is that the density is lower than that of NAND, the cost is extremely high, and it is mostly used in enthusiast desktops and data centers.