Just upgraded CPU, now have instability

[Enhanced_Interrogator]

Hey guys, I ran prime95 with my new CPU (p4 northwood 3.4ghz, previously 2.8 ghz) with the large FTT test (the one that tackles power, CPU, and memory heavily) and had a system crash. It's also been crashing with various game benchmarks.

I think the problem is that my motherboard is having trouble either supplying or regulating enough voltage for BOTH my memory and CPU.

I'll give you guys a timeline of my upgrades, which thus far have their own threads on this forum.

I installed a hd 3850 AGP GPU.
http://www.tomshardware.com/forum/274028-33-power-supply-molex

I upgraded RAM with a 512 dual channel kit and had to volt-mod to make my memory stable at factory settings.
http://www.tomshardware.com/forum/265459-30-volt-make-memory-stable-option-boost-bios

Now I replaced my p4 2.8ghz northwood with a 3.4 ghz version (both have 800mhz FSB's)

Now I get the crashes, but only when I have all 1.5gb RAM in. When I took everything out except one 512 stick, everything was stable.

Any suggestions or ideas are greatly appreciated.

My rig:
P4 3.4ghz
Intel d875pbz mobo
HD 3850 AVAGP
Audigy 2
cheap netgear pci wireless card.
antec power trio 550

 

[mi1ez]

have you cleared the CMOS memory?

You may need to manually look up and key in the voltage in the BIOS

 

[Enhanced_Interrogator]

Thanks mi1ez. I removed the CMOS battery for 10 mins last night. When I plugged everything back up, I got zero errors in prime95!

However... this morning everything went back to being really unstable. I have a few benchmark programs that were crashing my system.

I know the problem has something to do with the memory side of my motherboard. Whenever the CPU and memory are chugging near full load, the memory gives out (I know this because when my comp restarts it mentions memory failure).

Maybe the small volt mod I did to my memory voltage regulator made my motherboard unstable? Or maybe I need to give another 0.05v or so to the memory? I think it may be the latter because my system is pretty stable with one stick in. But maybe my mobo just can't handle the higher memory voltage because it was designed to stay around 2.5v. I can't key voltages into the BIOS, thats why I did the mod.

 

[Enhanced_Interrogator]

Ok guys, the early revision of the d875pbz is a sissy board. I just upped the memory voltage another .05v and the system became even more unstable.

So I've erased my volt mod (literally, with a pencil eraser), and now my system is running completely stable again. Of course, now I don't have enough voltage to use the factory timings on my memory.

What do you guys think I could do to stablize my board with a small memory volt-mod. Should I mod my vcore as well, would that even everything out?