Just a general Q about gfx cards really. My current 6600GT is oc'd to 550MHZ and 1150 for the memory. I'm selling up for a PCI-E sapphire X1950 pro, which is 580MHZ/1400. Is it the speeds of the cpu/memory alone that determine the performance of the graphics card, or say if you could theoretically clock my current card to the x1950 pro speeds, would it still fall short?