On my P4S533, my 9700 Pro (v 1.1 built by ATi) doesn't like anything over 74MHz. I used to be able to oc my P4 1.6a @153fsb with an ATi Radeon 8500. Once I dropped the fsb to 149MHz (149/4*2), it works like a champ. IMHO, your best bet is a mb that has a agp/pci lock at 66/33.