I have two xfx 5770's in crossfire and i was wondering if i should overclock them and would it make much a difference in terms of performance in gaming? I have never OC before but i understand the basics. I have MSI afterburner but im scared to up the settings. right now they are sitting at 850/1200. if i bump it to lets say 930/1300 or higher would i have to turn the voltage up and to what? 1200? Also how will i be able to tell if after OC the cards, its hurting my computer or its not stable? is there a way to tell? it would be nice if someone can help me out with a good OC without hurting the cards or my computer.