Stable 3.0Ghz OC but 8800GTX crashes

[Walala]

Hi guys, I'm fairly new at OCing so some advice would be greatly appreciated.

First off, my specs:

Case: Silverstone Tj09
Mobo: Asus P5N-e SLI (0803)
CPU: Q6600 G0
RAM: 4x2gb G-skill ddr2-800
Vidcard: Asus EN8800GTX (stock cooling)
CPU cooler: Arctic Cooling Freezer 7 Pro
PSU: Silverstone 750W
OS: Vista Ultimate 64-bit

I can get it to 3.0Ghz stable and I've stress tested with Prime95 for 10 hours which it passed with flying colours.

vcore: 1.41
mem voltage: 2.1-2.2
nb voltage: 1.7

Temps at that speed for the cores are around mid-high 30s and up 45-50 under load. The GPU idles at 60 and 75 on load(which is hot i know).

Problem is, when running on the 3.0Ghz OC, 10-15 secs into playing a video, the system crashes with a BSOD (Hardware failure: system halted message). Right now, I've got the system running at 10% AI overclock (2.64 Ghz) with similar temperatures but the video card doesn't crash when playing games or watching videos.

I've replicated that crash plenty of times, so i'm fairly sure its the video card. So, my question is, would getting a GPU cooler fix the problem? I'm inclined to think that the video card is just overheating.

Can an overclock actually cause the video card to crash like that? I read a forum the the PCI-e frequency could be the cause, but i don't know enough about that......

 

[Mondoman]

Maybe, or more likely you don't really have a stable OC, and using the video card is using parts of the MB that Prime95 didn't stress test.

 

[Walala]

hmmmmm......i just tried setting it to 2.7-2.8 Ghz and windows wouldn't boot.

I'm using sync mode (1:1) btw.

i might try downgrading the BIOS, i've read the 0608 revision is a lot more dependable

 

[calinkula]

Using the AI program to do all your overclocking automatically? I would suggest you get familiar with a few bios setting. First thing I would do is go into bios and lock the PCIe bus at 100.

Actually you could do all your OC in bios if you wanted. That's how I do it, I find it quick and easy. Although I used to OC when you had to physically move jumpers on the mobo. That was a pain.

 

[megabuster]

What's the wattage on your P.S. and did you disable all EIST and other underclocking Bios functions. Make sure your pci-e is locked on 100Mhz in bios. You can use rivatuner to manually adjust fan speed of geforce card fan to 50% it should be enough to deal with heat.

 

[Walala]

funnily enough, I can't find a setting to lock the PCIe bus. its just set to 100.

750W PSU. I've got EIST on, i left it on based on some other forums posts i read....

 

[Walala]

well i've tried it with EIST off, still boots fine into windows but still getting the BSOD when playing a video.

sometimes i get a memory parity error, but most of the time it just says hardware malfunction. ill do a memtest later on.....the constant BSODs are draining me =(

thanks for all the help so far guys