Do the SPD settings of PC133 CAS3 make the BIOS default to CAS3 on a 100 FSB machine? (I can't adjust the timings.)

Eug

Lifer
Mar 11, 2000
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I got a 512 SODIMM from Crucial for my iBook which was PC133 CL3 simply because PC133 CL2 was unavailable. (PC100 CL2 was also unavailable. It seems all their 512 SODIMMs are set as PC133 CL3.)

Does the CL3 setting on the PC133 RAM tell the BIOS to run at CL3 despite the RAM being 7.5 ns? Or would the BIOS "know better"?

I'm starting to wonder if I should have looked elsewhere for 8 ns PC100 CL2 since my FSB is 100 only anyway. You can't actually manually set the CAS memory timings on these machines.

I can't really test this on my desktop, since all the SDRAM desktop memory I've bought lately is PC133 CL2 anyway.
 

nortexoid

Diamond Member
May 1, 2000
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most will default to CAS2 @ 100mhz bus/mem speed.

some will default ot CAS3 if u raise it any past 100 - i.e. 101.

and then i believe there is some really crappy stuff, though rare, that defaults to CL2 @ 66mhz.
 

Eug

Lifer
Mar 11, 2000
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Thx. I wonder how my iBook deals with it. I'm hoping it does default to 100-2-2-2 even with the 133 Cas 3 SPD setting.

Dunno though.