Ive just tried modding by asus x800 pro vivo card to a XT PE using the asus bios. But this has made the card very unstable. Im using the new artic cooler as well. Could this because my psu cant take the extra strain. my system is: P4 3.0 ASUS P4P800 1 GIG DDR 400 Crucial 380 Watt Power Supply I havent tried the XT PE Clocks with only 12 pipes enabled yet. Also can u use any bios or do you need to use your manufacturers bios.