I got an X800XT which was at 500/500, i then flashed it to a XTPE bios and it was at 520/540. I then decided to installed the artic silencer rev 2. my idle temps are now about 29 degrees c, on a load it never gets over 50 and thats at a push. Ive managed to push it to 540/580 and it stays at the same temps. Any further and i get artifacts, but why, its cooler then its ever been even at standard x800xt speeds. Please help.