What is a solid state drive

• What is a solid state drive

Solid state drive, or SSD for short, is a computer storage device that mainly uses Flash memory (NAND Flash) as permanent memory. Solid-state drive consists of control unit and memory unit (FLASH chip, DRAM chip), widely used in industrial control, video surveillance, network monitoring, network terminal, navigation equipment and many other fields. Relative to mechanical hard drives, solid state drives have higher read and write speeds, but also relatively high cost. The new generation of SSDS use SATA-III interface, PCIe x8 or mSATA, M.2, ZIF, IDE, U.2, CF, CFast and other interfaces

• Hard disk comparison

  The interface specifications and definitions, functions and usage of solid state drives are almost the same as that of ordinary hard drives, and the shape and size are basically the same as that of ordinary 2.5-inch hard drives.

  Solid state drive has the characteristics of fast reading and writing, light weight, low energy consumption and small size that traditional mechanical hard disk does not have.

  
  

Due to the different design and data read and write principle between SSD and common disk, the internal structure of SSD is also very different. Solid-state drives (SSDS) are generally simple and detachable; As a result, most of the articles we see about SSD performance evaluation are accompanied by internal SSD disassembly diagrams.

On the contrary, the data read and write of the common mechanical disk rely on the air flow generated by the high-speed rotation of the disk to hold up the magnetic head, so that the magnetic head is infinitely close to the disk without contact, and the stepper motor drives the magnetic head to read the data through the lane change. Therefore, its internal structure is relatively complex, but also more precise, generally not allowed to disassemble. Once manually removed, it is highly likely to cause damage and the disk will not work properly. This is why we rarely see disassembly diagrams when evaluating disks

• Fast read and write speed

Using flash memory as the storage medium, the reading speed is faster than mechanical hard disk. Solid-state drives use no head and have almost zero seek time. The continuous write speeds are amazing, and most SSD vendors will claim that their SSDS have sustained read/write speeds of over 500 MB/s! The speed of solid state disk is not only reflected in continuous reading and writing, random reading and writing speed is the ultimate meaning of solid state disk, which is most directly reflected in the majority of the daily operation. This is related to extremely low access times, with the most common 7200 RPM mechanical hard drives typically having seek times of 12-14 ms, whereas solid state drives can easily reach 0.1 ms or less.