Extreme necro, but i'm doing this for future reference: Just tried my QHZK xeon 5050 (dempsey) engineering sample on my asus p5k-vm. Worked straight away, no issues with fsb. runs at the native 667mhz. Oh - and the dempsey chips i've tried work just fine, even ES. microcode is a bit of an issue …

Extreme thread necro but just letting you guys know that the ECS P4VMM2 supports AGP 3.3v cards as well as 1.5v ones. If you have the right revision you can use chips with a 533Mhz FSB.