Terrible Video: Motherboard issue?

[HeroIgnored]

Problem:
Very poor graphics performance after major hardware upgrade.

Alright, first off, here's what I've got:

Gigabyte M55SLI-S4 - motherboard
AMD 64 FX 5600+ - CPU
nVidia 8800GTS (MSI, 320meg vram) - video
G-Shock 2 gig (2x 1gig dual channel) - RAM

Let me know if there's anything else in the way of system info. I'm pretty new with the hardware support in forums thing

I've just recently upgraded my system, so I put a fresh XP install on my system and booted up. Had a few problems with random restarts and odd booting sequences, but was able to fix those with a bios upgrade. So, I installed the latest nvidia 8800 drivers and then installed and ran Oblivion to see how my upgrade would improve gaming. Holy crap, I was able to load a game and, after being able to play for about half a second, the screen locks up and my displays go haywire.

I think it may be my motherboard, though I'm not sure. My cpu seems to be running fine. I ran CPU-Z and found no issues there. The graphics card would be my other suspect, but I thought I'd check and see if anybody had any ideas first.

Thanks in advance.

 

[HeroIgnored]

Quick update:
I installed Company of Heroes to make sure it wasn't just an Oblivion issue. Again, I ran the game and didn't even get to the main menu. The game started up, never got past a black screen, and after a few seconds my computer rebooted. I'm pretty frustrated and not sure what to do.

 

[Apokalipse]

I'm thinking it might be driver related.
I have an 8800 GTS 320MB, and I found the drivers that work best are 101.09
*edit*
you can get them here

I have used 158.xx and 160.xx drivers, but I always get reduced performance over 101.xx

 

[HeroIgnored]

Thanks for the quick reply. I'll give that a try tomorrow.

 

[Apokalipse]

Thanks for the quick reply. I'll give that a try tomorrow.

I got it wrong, it's actually 101.02.
101.09 doesn't support 8 series cards.

 

[decibaL]

run memtest

 

[HeroIgnored]

Alright, I installed the 101.02 drivers and everything with the install went fine. I ran oblivion, and everything was going smoothly until it came to the point to load a game. As soon as the load game screen popped up everything froze, and then after a few seconds I received the Blue Screen of Death (XP style). It didn't give me enough time to read through it before my system just rebooted, but I did see something n4 (Like the chipset?). I'm really concerned about how this will effect my hardware if this keeps up, as I am experiencing TONS of reboots every time the system starts to have video issues.

 

[HeroIgnored]

Okay, just an update. I ran OTTC, and it said I have a faulty processor. I also ran MemTest86+, which said that there are some errors in my memory. I havn't stopped and checked each DIMM slot and each chip separately, but I was wondering if a bad processor could have effected the memtest results?