P4C 255 FSB freezes after 24-36hrs...

HELP! My new build, (you rememeber the one: Asus P4P800, ADATA PC4000, P4C 2.6GHz) runs rock solid at 255 FSB ~3.34Ghz *BUT* it locks up after 24-36 hours, which isn't particularly desirable...

It doesn't reboot - just locks/freezes. If the monitors are powered off I can't bring them to life by wiggling the mouse or banging on the kb. If display is still on, there's no mouse movement or any kb response (think the Num Lock light comes on/off but not the other 2). I have to hit the reset switch.

It's not overheating - I'm recording history in ASUS Probe and CPU is ~40 degC, MB is about ~35 degC.
It's not sitting idle but is SETI crunching. Running XP SP1. Radeon 7500 gfx ( :eek: )

I've no idea whats up, so I'm taking the bus speed down a little each time to see if there's a point at which it'll stop doing this. It's currently down to 252 3.27GHz. Next stop 250 then will probably go in down 5MHz steps.

Anyone got any ideas???

I think what you are doing is a fairly good idea. You could try stress testing it more than just crunching seti, try running the prime95 torture test and toast alongside seti, that'll give it something to do! How often has it done this? It does seem a little odd to crash at that speed and temperature, prehaps some more voltage is in order, what voltages are you running at at the moment?

It's done this about three times now.

I have Prime95 torture tested it, just until it completes the cycle though (2-3hrs) to make sure it's not returning bad numbers. Guess I can fire it up again and let it run - any favoured test or just a blend of the 3?

What's this "toast"?? Not heard of that one. Point me to it and I'll give it a try.

Vcore is showing at 1.664v, although I thought I'd set the BIOS to 1.675 (doesn't Asus usually overvolt, not undervolt?)
Vdimm I think is set to 2.75v (the one before the max option - a desperate measure hoping it'd help things!) - although I can't see this reported anywhere so will double check next time I have to boot it!