I have asus eah 4850 and it isnt need oc. On this card i play all games @ max(exept crysis). Why do you need oc if this card still have a potensial.
P.s fan speed always @ 60%, 100% it is very loud for my.
P.p.s with new bios it clocs on 2d mode are very low but on 3d clocks are nrml.
you can oc you cpu to 3.6 ghz on stoc.
i done it yestarday