I've read many a place that 1.5 is fine for that chip....i've got mine at 1.45 at 3.750GHz and decided thats good enough for me....untill new chips come out and mine looks even weaker that is lol. Theres no real need to push it farther than that unless you are going for bragging rights, at that speed it'll handle everything fine. The only way you'd see a differnce is if you do some very processor intensive stuff on it....I know for me every MHz speeds up MATLAB which is why i OCed in the first place, FFTs are lightning fast now...well maybe not that fast but still...but I still don't wanna push it any farther