Solid-state drive parsing

In 1956, the first hard disk was created! And for a long time, the dominant market for computer hard drives was dominated by hard drives (HDDS), which are bulky and cheap.
HDD is a mechanical structure, resulting in low bandwidth, high delay, poor shock resistance, high power consumption, loud noise, large volume and weight, and long working time will produce wear, it is easy to cause computer lag. What to do?

To solve these problems, solid-state drives (SSDS) using entirely new semiconductor storage technology hit the market in the 1990s. Different from HDDS, SSDS are mainly composed of controllers, memory chips (Flash chips, DRAM chips), and there are more ways to connect SSDS to computers. Compared with HDD, the advantages are significant:

■ Fast read and write speed: high continuous read and write speed, random read and write speed, very low access time.
■ Shockproof and anti-fall: The possibility of data loss can be minimized when moving at high speed, flipping and tilting, bumping and shaking.
■ Low power consumption: power consumption is much lower than the traditional mechanical hard disk.
■ No noise: no mechanical transmission device, the noise value is close to 0 dB.
■ Wide operating temperature range: most products can operate at 0~70 degrees Celsius.
■ Light: much less weight and size than mechanical hard disk.

What was it about the fledgling SSD that quickly overtook the HDD?
SSD appearance evolution: Small and thin
Initially, SSDS were made large and thick to accommodate the interface and space of traditional HDDS. However, the actual SSD internal circuit board is very small, and after continuous development, the latter two are now popular: 2.5-inch and M.2 interface.

Internal SSD decryption: Controller + memory chip
The SSD controller is responsible for the completion of internal SSD instructions, undertakes the entire data transfer, and connects the memory chip to the external interface. In addition, load balancing of data on each memory chip can be properly allocated so that all memory chips can work in parallel under a certain load to coordinate and maintain the collaboration of different chips.

Memory chips are the foundation of SSDS, which ensure that data can be stored even after power failure. FLASH chips are commonly used as memory chips. How do flash chip-based SSDS work?
SSDS typically have multiple flash memory chips, and the controller decides which flash chip the data is ultimately stored on. The reading and writing of data inside the flash memory chip is regular: each flash memory chip contains many blocks, each of which is divided into multiple pages, and each Page contains many cells. Access is in Page, and clearing is in Block.

If you think of the Cell as a room, more people can go in and more capacity can be expanded. According to the amount of data stored, it can be divided into SLC/MLC/TLC/QLC. SLC stores 1 bit of data (2 states), MLC stores 2 bits of data (4 states), TLC stores 3 bits of data (8 states), and QLC stores 4 bits of data (16 states).

In order to further expand the capacity of flash memory, 3D NAND technology began to be used in flash memory chips. Just as flash memory chips used to be bungalows, 3D technology now allows data to live in high-rise buildings. The amount of data stored per unit area is multiplied.

SSD interface iteration: Multiple interfaces for connecting computers
Early on, in order to better upgrade and replace traditional HDDS, SSDS used the same appearance size and interface specification as 2.5-inch HDDS. Both are SATA data interfaces, that is, serial SATA communication buses.