my system is quite stable after a 50% oc and am running corsair xms2 1066 ram which get unstable and screw up my oc the moment i try to manually set the frequency ( even to 800) . So now am running it at 400 - 4-4-4-12 . So basically there is no point in me trying to get 5-5-5-15 1066 eh . Rig only used for games.
cm2x2048-8500c5 is the ram
and p5ql-pro is my mobo (p43)
Not really, I was in a similar situation as you a while back. The only difference i saw between the two was in video encoding, where the higher bandwidth ram was faster. For gaming you wont notice a difference. Ideally go for a mixture of the two, highest stable frequency with the lowest stable timings. Might take some time tinkering, but might be worth it.