What's CPU doing when you are performing MemTest?

Does the CPU do anything while testing Memory? If my bios vcore is at 1.55 in order to test my pc4000 at 245, does this mean my CPU is idle at 1.55? I have a 3.2E that's why I am concern about the 1.55. Is there a better way for me to test my pc4000 at 250 with p4p800 & 3.2E?

update:
when i said 1.55 in order to test, i mean at 1.55 i don't get any error with 245 fsb.


thanks,
~joy

no one knows?

anyone???

I am guessing the CPU is doing the checking and azalyzing of the memory patterns