DRAM Types

•          FPM RAM

•          EDO RAM

•          SDRAM

•          DDR SDRAM

•          RDRAM

•          VRAM

•          WRAM

      FPM RAM

•          Fast Page Mode Random Access Memory

•          Access speed = time taken for FPM chip to supply Northbridge with data – measured in nanoseconds

•          60ns is faster than 100ns

EDO RAM

•          Extended Data Out Random Access Memory

•          Early 1990’s – used with some 486’s and with Pentiums

•          Came in 72-pin SIMM or 168-pin DIMM

•          Needed special Northbridge design

•          Needed less refreshing than FPM RAM so data was available to the processor more often

•          Maximum transfer rate to L2 cache is 264 MBps.

•          Used throughout the 1990’s

Eventually replaced by SDRAM