6950 crashing in games, but its not the GPU. Help!

[Stones42]

Been struggling with 6950's for a while now, I've RMA'd 2 of them, and I'm on my 3rd now - each one has had a slightly different problem.
Upgraded from HIS HD4870 (which has never had any problems) to a Sapphire HD6950 1gb. It would not POST, pretty sure it was genuinely faulty.
They replaced it with a Sapphire 6950 2gb, non-reference. It would flicker in windows, or while gaming, and would crash with a black or blue screen every 5-15 mins.
I RMA'd that one, and they've replaced it with a Sapphire 6950 2gb reference model (with the BIOS switch). This one is stable under windows, but will crash within 5 mins while playing any game I've tried (DX10 or 11)

So now I'm thinking that the video card isn't the issue, here are my other specs:
Win 7 Pro x64
Gigabyte GA-780G-UD3H
AMD Phenom 9750 x4 2.4Ghz
4GB DDR2 800
Corsair CX600v2 80+ certified PSU

So far I have tried:
-Flashing mobo BIOS to latest version
-Upping GPU voltage to 1.11V and 1.115V (factory is 1.1V)
-Catalyst 11.11, 11.12, 11.06 - completely uninstalling between each one
-Tested under Win 7 x64 and Win XP x32 (on the same machine)
-Removed all un-necessary hardware
-Tested ram in different slots
-Tried Both BIOS's on the reference card
-Currently doing a fresh Win 7 install


Anyone got any suggestions? I'm thinking it must be the PSU or mobo. My guess is PSU, even though 600W should be plenty and it has 2 x 6+2pin 75W PCI-E connectors. Willing to try almost anything, this is driving me crazy!

 

[geekapproved]

I would have suspected the psu after the second one, but I would have tried a fresh windows install too.

I gotta tell you that with that cpu, your never going to see the 6950's full potential.

 

[bloc97]

Hmmm. Are you sure that you have plenty of space and that your GPU is not overheating? A 6950 should produce a lot of power and heat.

Btw did you plug in the extra power cables? The 6-pin or 4-pin ones?

 

[Stones42]

*Update*
Did a fresh Win 7 install on a new HDD, the only thing I installed was the driver that came with the gpu and Portal. Crash within 1 min of opening portal.

GPU is idling at 45 and I haven't even seen it in the 60's while gaming. It's just being powered by 2 x 6pin connectors straight from the PSU. BIOS reading show the 12V rail is supplying 12.24V. The 3.3V is only reading 2.880V, could that be an issue? I'm really suspecting the PSU now, but how can I prove it?

 

[lunyone]

I'm for the PSU, but could possibly be the mobo, but it would be less likely. If you can borrow another friends PSU and test it, that would be the best option. I've been reading Corsiar's latest PSU's CX400w-600w one's and I'm not seeing very good reviews. I'm not sure if they switched vendors for the CX models, but I'm really not impressed. The previous versions didn't seem to have the issues that the newer ones have (mind you this is just from reading and not from actual experience).

 

[Stones42]

I can test the card in another system tonight and will let you know how it goes. Luckily my PSU is only a couple of months old so I should be able to return it (and upgrade to a better one hopefully)

@geekapproved : Yea the CPU is aging, I'm planning on upgrading to an i5 2500k, but not for a few months. Hopefully I can get this issue sorted before then!

 

[bloc97]

*Update*
Did a fresh Win 7 install on a new HDD, the only thing I installed was the driver that came with the gpu and Portal. Crash within 1 min of opening portal.

GPU is idling at 45 and I haven't even seen it in the 60's while gaming. It's just being powered by 2 x 6pin connectors straight from the PSU. BIOS reading show the 12V rail is supplying 12.24V. The 3.3V is only reading 2.880V, could that be an issue? I'm really suspecting the PSU now, but how can I prove it?

No you shouldn't be worried about the 3.3V rail (For the GPU) since it isn't the one that is supplying the GPU, but I would be worried for my motherboard since it is supplying a part of it, and it may be an issue since it touches the South-Bridge (PCI-E Controller) and it is far greater than the 10% difference allowed for a PSU. (2.9V is an HUGE difference compared to 3.3V)

My 3.3V is at 3.36V currently.

Also, your 12V rail is supplying more than 12V, it generally means that you have an pretty decent PSU, but it may be a exception for this time. :/
Cheap PSUs tend to supply just a little under 12V in the 12V rail. (~11.87V)

Here is the PSU Voltage Tolerance Table :

Supply [V] Tolerance Range (min. to max.) Ripple (p. to p. max.)
+5 VDC ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV
−5 VDC ±10% (±0.50 V) –4.50 V to –5.50 V 50 mV
+12 VDC ±5% (±0.60 V) +11.40 V to +12.60 V 120 mV
−12 VDC ±10% (±1.2 V) –10.8 V to –13.2 V 120 mV
+3.3 VDC ±5% (±0.165 V) +3.135 V to +3.465 V 50 mV
+5 VSB ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV

 

[Stones42]

*Update*
Tonight I swapped my PSU for a 560W Cooler Master PSU from an old PC (don't have the model number right now sorry). I've played all of the games that were crashing with my Corsair CX600v2 with NO ISSUES. So far, it looks like my problem is sorted. For all those other people who have had crashing issues with their 6950's - CHECK YOUR PSU! I bought the Corsair specifically because I thought it could handle this video card, but apparently it can't.

Thanks so much for your help, I'll update again with any more info.

 

[lunyone]

*Update*
Tonight I swapped my PSU for a 560W Cooler Master PSU from an old PC (don't have the model number right now sorry). I've played all of the games that were crashing with my Corsair CX600v2 with NO ISSUES. So far, it looks like my problem is sorted. For all those other people who have had crashing issues with their 6950's - CHECK YOUR PSU! I bought the Corsair specifically because I thought it could handle this video card, but apparently it can't.

Thanks so much for your help, I'll update again with any more info.

The Corsair brand PSU's are pretty good, but like I stated before the CX versions (400-600w) recently made ones haven't been getting good reviews. This just points out that what I've been reading about them has been pretty accurate. I like Antec/Seasonic/PCP&C for quality PSU's and the Corsair TX series is good too, so don't rule out Corsair in the future, just stay away from the CX versions, if you stay with a Corsair brand (RMA opitons).

 

[Stones42]

*Final Update*
I returned the CX-600v2 and upgraded to a Cooler Master GX650, everything seems to be running fine. Hopefully this can help other people who have been having similar issues, I'll definitely be staying away from the Corsair CX series from now on. Thanks for all your help!

now get a real or better processor and maybe then you can be considered a gamer..

Grow up, I've been gaming for 20 years.

 

[Stones42]

Best answer selected by Stones42.