I'm currently tweaking my pc which is an Thunderbird 700 (unlocked) and the new abit kt7-raid. I've managed to tweak it as high as 950 with the core voltage set at 1.85v, very similar to Gene of ocaddiction.com when he overclocked his board and ran a review of the mobo. The problem is that my cooling unit is not particularly the best one (its a Vantech) and I think it runs too hot for my tastes but still stable. If I want to set the CPU at something lower like 800 or 850 what core voltage should I go with?