I think 500 FSB is a no-go for thi9s mobo + Quad....even 500x6 is throwing in errors and lockups with stress testing.Tried each and every combination of voltages,taking NB from 1.43 to 1.73 - to no avail.So, I am happy sitting here at 495 x 8.5 and trying to find stability with the 0902 BIOS and reducing voltages bit by bit.