On my xp1700 b I can run prime forever, but games lock up in just a few minutes. In this case, I wouldn't recommend Prime AT ALL. It did give me errors, eventually, but that was well beyond the point when a game would freeze; I could run Prime at 1.99xghz @1.70v w/ no troubles. After a couple hours of gaming, it would freeze at 1.825ghz @ 1.85v. Test your rig w/ everything, and if ANYTHING doesn't work (as Siliconx, and I'm sure many others have said), you've pushed a bit too far. You might miss a couple hundred points in a benchmark, but you won't likely miss all the errors and freezes...