Static random-access memory

A static RAM chip from a Nintendo Entertainment System clone (2K × 8 bits)

Static random-access memory (static RAM or SRAM) is a type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed.

The static qualifier differentiates SRAM from dynamic random-access memory (DRAM):

  • SRAM will hold its data permanently in the presence of power, while data in DRAM decays in seconds and thus must be periodically refreshed.
  • SRAM is faster than DRAM but it is more expensive in terms of silicon area and cost.
  • Typically, SRAM is used for the cache and internal registers of a CPU while DRAM is used for a computer's main memory.