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Memory Types ?

By HW-Tech ·
Where can I find out what what memory types such as PC133. PC2100, etc are ? Such straightforward info eludes me!

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by TheChas In reply to Memory Types ?

Kingston ( has a general FAQ that gives good basic knowledge of the different memory types.

Their are 4 types of RAM in 'common' usage at this time:

72 pin SIMM

168 pin SDRAM DIMM

168 pin DDR RAM DIMM

184 pin RDRAM DIMM

Within each style, there are different types and speeds.

SIMM types:
FPM Fast page Mode
Parity FPM with a parity bit
EDO Enhanced / Extended Data Out

SIMM speeds:
80 ns, 70 ns, 60ns

SDRAM DIMM speeds:
PC66 66 MHz
PC100 100MHz
PC133 133MHz

DDR Speeds:
PC1600 160MHz
PC2100 210MHz
PC2600 260MHz
PC3300 330MHz

RDRAM speeds:
400 MHz
800 MHz

Then, there are variations in the density of the memory chips on the modules.
Many a system that uses SDRAM DIMMs has problems with the on-going evolution of the SDRAM standard.
There are at least 3 different 'generations' of SDRAM. Not all motherboards can use all of the different variations.


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