Question for experts - memory and memtest86

[vietdeity86]

Ok, I bought a new computer and this is my 4th custom build. I'm certain i know what it is but I wanna make sure.

DFI P965-S infinity
scythe 120mm heatsink
e6600 (b2 stepping, L70 model)
4GB (4x1GB) Crucial Ballistix PC8000 @ 2.2 @ 5-5-5-15
antec p180b case
Ultra infinity 600w PSU
8800 GTS 640
Windows XP 64 bit
Raptor 150GB drive

I can boot to windows, but sometimes when I stress it even a little or try to run orthos, it restarts (even at slightly above stock speeds, 2.8) LAME, so I think something is wrong with either my PSU/mobo/memory.

I go in and I swap my PSU from my other comp (Thermaltake toughpower 700w) and it does the same thing.

Next step, run memtest! I do test2 and it runs fine... @ 3042 mhz cpu speed.

Nope, still restarts, so I'm sure I have to do the full default memtest to test every memory factor. I then think, hey, maybe the 4GB is interferring. I turn off comp, flip the power switch, and hit the power button to empty the caps. Then I proceed to remove the memory... the things are HOT! I'm running them @ 840 mhz @ 5-5-5-15 with 2.2 volts... WEIRD. So I take all but 1GB stick and run memtest. Fail fail fail fail, im like crap, that's my problem... put in another stick... fail... put in my other sticks... fail.

What next? Well, I take out my patriots from my other comp and put it in (i know it works cuz I did the full 8 hour wall test for these) and it fails also.

Runs about 2-3 times hotter than in my other computer. Is it my VTT voltage off or what.

I THINK it's the motherboard, it's been giving me all sorts of problems. Dig in boys, I need this computer ASAP for my brothers business. (Graphic applications and rendering stuff. Photoshop/corel etc)

Oh, it won't even load past the bios screen for DDR speeds above 900, it'll lock up.

 

[Mondoman]

What happens with memtest86+ and Orthos if you don't run OC'd? If no problem there, it would seem that you're just trying to OC too much.

Potential issues:

I'm not sure exactly what type of CPU cooler you are using, but if you're not using a "downdraft-style" cooler (like the OEM Intel), the north bridge and the PWM circuitry around the CPU may not be getting enough cooling. Try using the OEM Intel cooler to check this.

The north and south bridges are passively-cooled. They may need active cooling for OCing.

Your GPU doesn't help your brother's business use and is likely boosting internal temps. I'd replace it with a 7000-series passively cooled card.