i think you might need a better cooler if you were going for 4ghz +,im at my limit with my cooler and two fans attached,80c you want to stay below on the cores,something like a prolimatech megahalems cooler would be better or one of corsairs watercooled units,but if your happy at 3.8ghz then its fine,there wont be much difference anyway from 3.8-4.2ghz