Geil dual channel 2x256 PC4000 RAM wont go 1:1 ratio at 250?

5 of my friends have tried my ram in their own computers, and all have gotten 250 stable, no problems. but then again, they use AMD and have 500W PSUs. my other friend used to have a p42.8C @ 3.5Ghz stable, and i tried my ram with his, and it worked fine at 250. any idea whats wrong with my setup?

thanks! (first time poster to these forums.)

If you ask me , right off the bat I would point at your powersupply . Also depends on how stable your rails really are and how stable your Vdimm is .

to the forums!

What CPU and chipset? I need more information