D0 3.4E - Was fine at 3.855, now problems

I went through a lot trying to get this CPU stable at 3.855. It would do 3.73 or 3.8 on air, but only with the AC blasting in the room and fans all over.

I got water cooling and my temp dropped from 65 load to 43 load and all seemed well until lately. For fun I decided to run memtest, and got an error on test 7.

To make a long story short, I tried everything from voltage increases/drops, timing changes, physical remounting, etc. only to ultimately find that the problem is not the memory or the NB, but the CPU.

I imagine its' the cache causing the errors...but I still keep getting them...at 3.855, 3.8 and now I am testing at 3.73 again.

I was stable before, what gives? This machine has primed for 30 hours, run hot cpu tester, and the like. now this.

CPU voltage is 1.4 in bios (up to 1.425 did not help) and mosfets are sinked and actively cooled as is the ram (which is cool to the touch). As you can see, PSU is not my issue...I use a OCZ 520.

Any ideas? I'm almost ready to drop this CPU and got for a 775.

Shane

how much vcore droop are you seeing under a load? maybe your getting too much droop and its effecting your stability.

what does cpu-z show your vcore at idle nad under load? sometimes bios settings dont give an accurate representation to the actual voltage your cpu is getting and from my experience with the p4c800-e boards i used they all had a fairly large droop to them.

how have you eleminated the memory/chipset as the culprit already?

have you locked the pci/agp down in the bios and disabled the speed spectrum?

I have officially ruled out the ram and the cpu. It is the cpu for sure. AGP/PCI is locked down and spread is disabled. Even most relaxed timings failed.

I am seeing the vcore droop to about 1.298 but never higher than 1.366 according to the bios (when set at 1.425).


...but memtest still fails...even at 3.73. I was fine even at auto voltage before (droop as low as 1.24) with no problems. Now this. It is stable at stock (3.4)...but thats no fun.

Shane

i cant help but think your not getting enough voltage to the cpu.

definetly add some more huice~

Will add juice when I get back from a trip I am on...but now I am remembering...

Doesn't memtest 5 and 7 errors mean RAM issues? ...and the others indicate CPU issues?

Shane