Cache Memory: SRAM

Another distinctly different type of memory exists that is significantly faster than most types of DRAM. SRAM stands for Static RAM, which is so named because it does not need the periodic refresh rates like DRAM. Because of SRAM's design, not only are refresh rates unnecessary, but SRAM is much faster than DRAM and fully capable of keeping pace with modern processors.

SRAM memory is available in access times of 2ns or less, so it can keep pace with processors running 500MHz or faster! This is because of the SRAM design, which calls for a cluster of six transistors for each bit of storage. The use of transistors but no capacitors means that refresh rates are not necessary because there are no capacitors to lose their charges over time. As long as there is power, SRAM remembers what is stored. With these attributes, why don't we use SRAM for all system memory? The answers are simple: