Rusty back down to 450FSB, hardly think it's mobo related... what are ya coretemps ? have you tried playing with one setting at a time ? most Q9450 users seem to need 1.6PLL and pretty high FSB Term voltage for 3.8Ghz ops... you can try to get with 6 multi as high FSB as you can... but I really think you got a mediocre performing CPU...