i hit 3.47 Ghz on water (link in sig). 3.5 is a crazy, crazy goal for aircooling. It is pretty much only going to happen if you have an extremely cool ambient temperature that allows you to crank the volts, but technically possible.

I remember people got some single core opties to 3.6 Ghz on air -- in the dead of winter with like -10C air Unfortunately now its summer. Unless you live in AUS?

Good luck with it