Ram Latency Question?

Nickus86

Distinguished
Mar 22, 2007
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If you have say pc2-5300 which is limited to running at 533mhz because of other pc2-4200 memory installed, does the cl stay at 5 for the 5300 or does it go down to 4 like pc2-4200 has a rating of?
 

Mondoman

Splendid
... does the cl stay at 5 for the 5300 or does it go down to 4 like pc2-4200 has a rating of?
Since 5 clocks at PC2-5300 is the same as 4 clocks at PC2-4200, you shouldn't have a problem either way; hopefully, the system will go down to 4 clocks.
 

Mondoman

Splendid
To clarify, the PC2-5300 CL5 RAM will work fine at PC2-4200 CL4 speed/latency. Whether or not it automatically gets set to PC2-4200 CL4 will depend on what's programmed into its SPD and on the MB BIOS. If it doesn't automatically get set to PC2-4200 CL4, just set it manually in the BIOS.
 

joex444

Distinguished
I would imagine the whole thing would default to CAS5 at PC2-4200.

The faster speed RAM should be able to match the timings at the reduced speed, so I would try changing the timings manually then making sure it does work, if CPU-Z doesnt report CAS4 on that stick at the slower speed in the SPD tab (lists all the timings at speeds programmed on the stick).

Depending on if the slower RAM is new or old, it might overclock to the faster RAM speed, but that's a gamble. I've heard of certain 667MHz RAM being overclocked to 900-950, so who knows (the RAM that did that had Micron D9's).