I agree. The autoOc usually will make the core too high. It will work, but after a few mins. of a good game, you will get artifacts or lockups. A real good way to OC is by 10%. For example: Stock 6600gt AGP, 500/900, go for 550/990 . Then inch it up a few mhz. at a time and keep an eye on temps. What I mean by a inch at a time is, try a setting for a whole day of computing/gaming, before you move it up. Just cause it runs at a certain speed doesnt mean it will for hours on end of Farcry or HL2.