Solid State Drives

A solid state drive is a storage device that uses solid state memory to store data. While technically not a disk, a solid state drive will often be referred to as a solid state disk drive, or a solid state disk, in reference to the fact that, in some ways, it replaces the traditional hard disk drive.

The principle behind solid state drives is that there should be no moving parts: no spinning platters, no moving heads. Data is split into word length pieces and stored in memory. It is then accessed almost instantaneously using unique system-wide addresses. This behaviour has been used in computer RAM for many years, but for a long time it was too expensive for manufacturers to consider using it as persistent storage in sufficient volumes to replace the hard disk drive.

Solid state disks use either NAND flash or SDRAM (non-volatile and volatile storage respectively). NAND flash is so-called because of the NAND-gate technology it uses and is common in USB flash drives and many types of memory card. NAND flash based drives are persistent and can therefore effectively mimic a hard disk drive.

SSD Drive

Read page 48 of the textbook “Exploring Computer Hardware”.