I had my 2700+ XP clocked to 2.31ghz for a long time, at far cry lets say I would get 35FPS at a certain part, after upgrading to a AMD64 3200+ I got about 55FPS at that part with my x800 pro. It was MUCH faster. Hope this helps any, could be mainly because the video card was being cpu limited, but I do think that the A64's are faster then the XP's or bartons clocked to the same speed.