Solid-state Drive

A solid-state drive (SSD) (often incorrectly referred to as a "solid-state disk" or "electronic disk") is a data storage device that uses integrated circuit assemblies as memory to store data persistently. SSD technology uses electronic interfaces compatible with traditional block input/output (I/O) hard disk drives. SSDs do not employ any moving mechanical components, which distinguishes them from traditional magnetic disks such as hard disk drives (HDDs) or floppy disks, which are electromechanical devices containing spinning disks and movable read/write heads. Compared with electromechanical disks, SSDs are typically less susceptible to physical shock, are usually silent, and have lower access time and latency. However, while the price of SSDs has continued to decline in 2012, SSDs are still about 10 times more expensive per unit of storage when compared to HDDs.

SSDs share the I/O interface technology developed for hard disk drives, thus permitting simple replacement for most applications.

As of 2010, most SSDs use NAND-based flash memory, which retains data without power. For applications requiring fast access, but not necessarily data persistence after power loss, SSDs may be constructed from random-access memory (RAM). Such devices may employ separate power sources, such as batteries, to maintain data after power loss.

Hybrid drives combine the features of SSDs and HDDs in the same unit, containing a large hard disk drive and an SSD cache to improve performance of frequently accessed data. These devices may offer near-SSD performance for many applications.