What are you trying to match VRAM speeds with your system RAM!? They don't have to match at all and are completly different. I have (kinda slow I know) 800MHz DDR2 system RAM, but overclocked GDDR3 VRAM to 1492MHz. It makes no difference whether your GPU RAM is the same as your system RAM. Your mate sounds like he has no idea what he's doing in all honesty.