I have Dual 6990s in my system and have recently been messing with fans and i want to know if I should look into setting a fan curve or something or if i should just leave it at one speed like ive been running Graphics card 1 fan at 65% and the other one at 60% and the second card is like 48C and the first one goes from 70-75C but does lowering graphics cards temperatures make the card run faster and or better or what does it do? Also is leaving it at 65% good? It seems stable at that like its pretty much 70-77C Please help