mixing PC100 and PC133

  • Thread starter Thread starter Gary Roach
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Gary Roach

I've got an old PII 266 with 64M PC100 SDRAM and i want to add 128M of
PC133. the BIOS only sees the PC133. I'm told i should upgrade the bios. is
this true? the sdram configuration setting in the bios was set to 12ns. i
switched it to 10ns to see if anything would change. it didn't. any idea how
to mix both the 100 and 133? thanks for any help.

gary
 
I've got an old PII 266 with 64M PC100 SDRAM and i want to add 128M of
PC133. the BIOS only sees the PC133. I'm told i should upgrade the bios. is
this true? the sdram configuration setting in the bios was set to 12ns. i
switched it to 10ns to see if anything would change. it didn't. any idea how
to mix both the 100 and 133? thanks for any help.

gary
Click to expand...

TO clarify, with both modules installed you're only seeing 128MB total?
Have you tried installing only the 128MB module?

The typical problem would be that your memory is the higher density (than
your motherboard can/can't support) so the motherboard will only see half
of the 128MB module. So it might see 64MB of that module, plus 64MB of
the original module, for 128MB total. If that is the problem, the
solution is buy PC100 memory instead... typically that costs a lot more
but is the way the lower-density memory is marketed these days. Since you
really only needed PC66 for the PII266, it is no performance penalty, only
higher priced. Alternatively, you "might" be able to buy a high-density
256MB module, and similar to your present situaiton, the machine only sees
half of it, for the 128MB you need. However, I have only done so myself
on a select few boards and cannot guarantee stable operation, the PC100 is
the best bet.
 
you had it right - the old system doesn't recognize the high density ram -
guess i'll shell out some money for pc100. thanks
 
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