Strange system lockups during Heavy Graphics Stress

Ok, I'm trying to figure out if this is a cause of my Video Card or if its something else that is causing the issue.

Mobo:
eVGA 680i SLI (122-CK-NF68)

CPU:
Intel Pentium Core 2 Duo E6700

Memory:
4 x 1GB of DDR2 800Mhz Patriot Extreme LL (4-4-4-12) PC6400

VideoCard:
BFG 7950GT

I've got my CPU running at 3.25ghz stable... have not yet touched the factory settings on my Ram modules. And I have my Video Card running at (Core 608mhz, Mem 797mhz).

Now, this lock up issue has always happened even when the vid card was not overclocked. I've noticed that it always happens within the first few minutes of playing a very graphic heavy game while the Video card ram switches from the 797mhz to 1244mhz. During this time its not just the Frames that lock up, its the entire system. If I'm playing a racing game I don't have to worry about running into anything because the whole system completely stops, even the sound starts looping till it goes back into normal play. I do not see any artifacts and my system did run stability tests on the GPU giving it a passing score. My question is, is this a driver issue or possibly be because my ram has not been overclocked yet.. any seggestions?

state what psu u have....... might be some help

I appriciate the info, I'm currently at work so I can't post the details of my PSU, I can tell you its an Antec 500w HE, I got it about a year ago and I am planning to make a new PSU my next upgrade while I prepare for SLI'd 8800GTX's.

Here is some addl info about my system as far as an idea of power consumption.

1 160GB SATA (7200RPM) and 1 250GB SATA (7200RPM)
Audigy2 ZS soundcard
2 120mm Case Fans, 3 80mm Case fans.
1 Floppy Drive
1 CDDVD (Dual Layer) Read/Write

When I get home from work I will post the specs on that 500w PSU.

as stated in my original post... even stock it still locks up for several seconds then goes back to normal use.

I've done stable tests on the Processor, no problems what so ever.

Yeah, write down all your OC settings, reset them all to absolute defaults, or to the ones stated on the packaging. Then try again, if it still locks up then you know its (probably) not the OCing. If it doesn't then you know what it was. Then start putting your old settings back until it does it (one at a time - wherever possible) Hope that helps.

Try a friends 650w PSU aswell.

Here is a break down of my PSU
OUTPUT
Output Voltage +3.3V +5V +12V1 +12V2 +12V3 -12V +5Vsb

Max. Load


23A


17A


17A


17A


17A


0.8A
2.5A
Min. Load 0.5A 0.3A 1A 1A 1A 0A 0A
Regulation 3% 3% 3% 3% 3% 6% 3%
Ripple & Noise(mV) 50 50 120 120 120 120 50
Available Power 75.9W 85W 456W 9.6W 12.5W
Total Power 500W continuous output @ 50C ambient temperature


INPUT

Input Voltage


100Vac to 240Vac +/- 10%

Input Frequency Range


47Hz to 63Hz

Inrush Current


60A @ 115V , 100A @ 230V

Input Current


9A @ 115V, 4.5A @ 230V

Hold-up Time


20ms at full load

Efficiency
Up to 85%
115V - Full load 76%; Typical load 82%, Light load 77.9%
230V - Full load 80%; Typical load 85%, Light load 79.45%

EMI/RFI


FCC Class B

Ok, so I've spent a lot of the day tweaking and completely re-doing my Oc's. I wanted to get my Mem to a 1:1 FSB:Mem ratio. pulled my FSB to 1600 and dropped my CPU Multiplier to 9, giving me 3.6ghz. And I tightened down my mem timings to 4-4-4-12 (it was defaulted to 5-5-5-15 by my bios). The system did post however I started getting system errors in windows. I may have to mess with my Voltages alittle more but I would have thought that 1.5v to my CPU would have been enough for the 3.6ghz since I can run stable at 1.4v at 3.2ghz. So anyways, I restarted and dropped the multiplier to 8 giving me a 3.2ghz OC on my processor. The system is running stable. I dropped by Vid card oc to default, did some tests and then started ocing from there. Suprisingly enough I actually have achieved a higher overclock that DOES NOT cause any lock ups like my previous settings did. I'm definately going to have to keep testing diff levels of V on this processor to at least push it to 3.4ghz... I'm going to be deeply saddened if my E6700 can't even reach levels that i see E6400's reaching.

One strange thing with the overclock is that my built in system monitor shows an FSB of 2000, with my Ram running at 1000mhz and my CPU running at 4000mhz. I almost had a heart attack when I pulled it up and it said that... thank god CPU-Z is reflecting the actual settings.

So I assume the OC was the problem then, yes?