Originally Posted by looniam
IKR . .i want an old DX 10 card even though i have a twice as fast 570 with a just as fast 550ti for physX that uses much less power. /sarcasm
IIRC the 580s had problems with their VRMs. i have no problems OCing to 900 @ 1.1volts on my reference 570 but the 480s can reflash the BOIS to get higher volts and clock speeds but gets much hotter. so without a case that provides decent cooling the 570 would be a better choice but if the OP is interested in OCing, the 480 has a higher potential.
The GTX 580 has FAR superior VRMs to the GTX 570. Reference GTX 570's are very poor overclockers, or at least, they cannot maintain that overclock for long because of poor VRM design. I fear for you 1.1 volt GTX 570 if it's a reference model....
I WILL agree with you that the GTX 480 can overclock better than the GTX 570 can, and with less concern of blowing a VRM. I fold on the 480 in my sig at stock volts and 777 on the core. It DOES spit heat out like a monster, but luckily, I don't pay for power here at college.
The same may not necessarily hold true for the OP though.