Currently running a pair of gtx 470's in sli, oc'd to 750mhz core, would it be worth changing to a single GTX580 3gb model. Im mainly playing bf3 now, the current sli setup is just hitting over 1200mb of vram usage, ive thought about clocking the 470's a bit more, but that means a new psu. As my current 850w corsair may not just be enough with the setup i have, (seen a few users on here kill i7 mobos with 850w psus and dual 470's).