SRAM vs DRAM

Last Updated: 2021-11-19

S = static, D = dynamic

	SRAM	DRAM
how to store data	transistors	capacitors
periodically refresh	not needed	needed
speed	faster	slower
cost	expensive	cheaper
power consumption	lower	higher
usage	microprocessor caches	main memory
capcity	lower (in MBs)	higher (in GBs)
placement	processors	motherboard

Note:

• DRAM needs periodically refreshed since capacitors leak power, and it is sensitive to electrical noise. SRAM: No charge leakage since it changes direction of current through switches instead of leaking power through the capacitor.

SDRAM

Synchronous Dynamic Random Access Memory (SDRAM) is a type of DRAM that synchronizes with the CPU’s clock cycles, so the memory controller knows exactly when requested data will be ready to access. This cuts access time and improves memory performance.

DDR – The latest generation of SDRAM is Double Data Rate (DDR). DDR increases speed, reduces power consumption, introduces refresh mechanisms, and adds security functions such as CRC.