I started out with an AthlonII x4 620 at 2.6 stock and managed to push it up to 3.0. I did it in 100 megahertz increments and prime 95 tested for about six to eight hours each time to make sure it was stable. Was that long enough or should I have tested longer? I've heard you need 24 hrs to be sure, but I really only planned to do that when I reach the performance I wanted to make sure I'm rock solid. I'm running water, and I haven't touched voltage yet. Don't really plan to. All other settings are stock except FSB. Idle 25C full load 35.