Some of you want to know how much power is used when overclocking and/or gaming, so we did some testing. 366MHz FSB was achieved with 1.30V, 373MHz with 1.35V and 400MHz with 1.45V on the northbridge. The CPU ran at the default 1.3000V up to 3.00GHz, 3.20GHz required 1.4000V, 3.33GHZ 1.4250V, 3.66GHz 1.5000V and 3.73GHz 1.5250V Vcore. Faster memory give you a power penalty under load of 4-6W per GB and the speed increase is hardly noticeable.
Our testing should give you estimates, it depends on the power supply's efficiency and what other components you use in your system.