Memory Problem for X21

[wilsonhs]

Hi there.
I am not quite sure whether a PC133 -256 SDRAM module would work on my X21
My X21 is a built-in 128mb model, and i had heard that X21 should be using PC100 Ram
so i am not sure whether 133 module would be working on 100 slot or not.
thanks everyone

[rkawakami]

Some PC133 memory modules will work inside an X21 but it has to be "low density". The speed of the module is not really the problem since a PC133 module will be operating at the system's speed of PC100 (i.e., it downclocks). However, there's a major difference in one of the timing specifications which requires that you use 16MB components on the module. So, for a 256MB module, that means it has to have a total of 16 memory chips on board (16 x 16MB = 256MB). If the module you are considering only has 8 memory chips on it, then that one uses 32MB components (8 x 32MB = 256MB) and will not work inside the X21.