Ken Price wrote: >>> ICH7R + Intel® 82573 >>> >>> Memory: >>> Crucial 512Mb, 1Gb, 2Gb modules matched to above MB. >> >> according to Intel, this chipset supports DDR2 667Mhz memory only. if >> you're using two dimms they should be matched pairs for dual channel >> operation? > > Yes. I'm using matched pairs of DDR2 667Mhz. Hmmm. Actually, the > Celeron's are using DDR2 533Mhz ... according to Crucial these work in > this MB. Guess that's one more thing to try with the dual core > processors. you might just try running the 667Mhz ram at 533Mhz if there's jumpers or a bios setting. if this works, and htere are fine tuning settings for the ram, you might try the original 667 speed only add a clock to the CAS precharge (again, ift he BIOS has advanced manual memory timing options, some boards do, some don't) btw, have you tried running memtest86 on these systems ?