7950GX2 Only working on 1 GPU problem. Help Appreciated

[The Asgard]

Greetings,
While I have been playing with my new toy I have noticed occasionally that the performance suddenly drops by 40-50% for no apparant reason. Its like the SLI is breaking or one of the GPU's is shutting down. Intially this problem only occurred if I went into the Nvidia control panel but I updated the Bios on my P5W DH from 1001 to 1305 and it appeared the fix the problem. But benching this morning I have found that I still have the problem all be less frequent.

For example in normal operation 3D mark 2006 scores 55-60 on proxy, when its in this 1 gpu mode I get 30-33. Its the same in Fear, Normal 44-69-392, 1 GPU mode is 20-36-79.

All I have been doing this morning is monitoring the GPU temp via the Nvida Temp Monitoring page and putting some extra cooling over the card Via a 120mm fan.

Also when its in this state the fans don't spin up while underload. Very strange and I'm not sure it would be apparant unless you could actually see your FPS. The only way to get the card fully working when its in this state is to reboot.

I'm running a P5W DH with 1305 Bios. Latest Nvidia Official Drivers. Fresh Install of XP. Idle temp's around 55'c with load temps about 70-75'c

Anyone else having problems? Could just be a faulty board?

 

[Coolasmoo]

Sounds like a power issue, but ive only used the power hungry ATi range so i cant comment to much on Nvidia.


I was going to suggest setting PEg link mode to slow in bios but i cant see that doing much really. You could try running slot power to heavy maybe.

These sort of problems you could do with testing in a second PC really to compare , but its not always viable.

 

[The Asgard]

Sounds like a power issue, but ive only used the power hungry ATi range so i cant comment to much on Nvidia.


I was going to suggest setting PEg link mode to slow in bios but i cant see that doing much really. You could try running slot power to heavy maybe.

These sort of problems you could do with testing in a second PC really to compare , but its not always viable.

Well I was running an X1900 XT-X previously with no issues. My Tagan 580W is pretty amazing on all the rails with a slight overvolt on all even underload. Common on all Tagan 580's. I have a Seasonic 600W I could try but it doesn't feel like a PSU issue. I know there are a few using the P5W DH with no reports of problems. Very strange. Never used Sli before apart from a quick play with 2 6600 a couple of years ago.

Only got the card Friday so I will just send the thing back if I can't resolve today.

Its really strange that the card doesn't crash the OS when it does this. Its almost like its a controlled shutdown due to temps

Cheers for the input m8 will give your suggestions a try

 

[Ping]

what sort of temps are u looking at on both gpu,s. Could be throttling down the speed due too heat? Everest shows both gpu temps. It might be worth a look.

 

[Amidar]

I would say thats it's got nothing to do with the PSU,go into the conrol panel and make sure 3D Mark is set to "Single display performance mode" in the programs settings,as when you first install the driver it sets to "Multiple display performance mode" you find it set to this in all the games & benchmarks in the program settings as this seem's to be Nvidia's default setting.So what ever game or benchmark you use that has an SLI profile make sure you change it to "single display performance mode".
The other thing i have noticed is by using the classic control panel it seems half the SLI profiles are missing so if possible use the new control panel.

 

[Morfik]

Asgard, I have actually experienced problems like this too. That's part of the reason I was checking the Link Width in the other thread as I don't know what's wrong.

Whilst I haven't experienced it with benchmarking (probably as I dont do much of it) it tends to happen when gaming. Whilst I realise games are much less of a controlled environment for system load and it could be a million things I tend to notice that during a session of gaming there are prolonged times when my framerate cuts in half for no apparent reason. No I don't mean during a fire fight, I can be alone in an area of the map that I normally get 90fps in and for no obvious reason i'm only getting ~40.

I had several theories some of which may be complete rubbish and I dont really have any evidence for any but here goes:

a) A problem with my MSI 7950 gx2 - Seems unlikely as you have a different make

b) A problem with my motherboard - Possible, it's brand new and the bios is only at its first revision and it's known to have issues with Quad SLI so perhaps single 7950 gx2 performance is bugged too

c) Card overheating - I have good airflow through my case so it seems unlikely. As mentioned above Everest is the only program that can monitor both GPU cores though I have no idea if it's accurate as not even Rivatuner or the Official Nvidia Control Panel can do this. Temps of the inner GPU were hitting 110c or so during load, the cards brand new so i can only assume this is normal?

d) Conroe throttling - I had overheating problems so this crossed my mind but as you're water cooled and don't have this problem it can't be that

e) Power supply - I have a 700w FSP PSU so it's unlikely to be this


As I said, no idea if any of these ideas carry any weight, if you manage to solve it let me know.

 

[The Asgard]

what sort of temps are u looking at on both gpu,s. Could be throttling down the speed due too heat? Everest shows both gpu temps. It might be worth a look.

Will have a look at Everest cheers

 

[The Asgard]

Asgard, I have actually experienced problems like this too. That's part of the reason I was checking the Link Width in the other thread as I don't know what's wrong.

Whilst I haven't experienced it with benchmarking (probably as I dont do much of it) it tends to happen when gaming. Whilst I realise games are much less of a controlled environment for system load and it could be a million things I tend to notice that during a session of gaming there are prolonged times when my framerate cuts in half for no apparent reason. No I don't mean during a fire fight, I can be alone in an area of the map that I normally get 90fps in and for no obvious reason i'm only getting ~40.

I had several theories some of which may be complete rubbish and I dont really have any evidence for any but here goes:

a) A problem with my MSI 7950 gx2 - Seems unlikely as you have a different make

b) A problem with my motherboard - Possible, it's brand new and the bios is only at its first revision and it's known to have issues with Quad SLI so perhaps single 7950 gx2 performance is bugged too

c) Card overheating - I have good airflow through my case so it seems unlikely. As mentioned above Everest is the only program that can monitor both GPU cores though I have no idea if it's accurate as not even Rivatuner or the Official Nvidia Control Panel can do this. Temps of the inner GPU were hitting 110c or so during load, the cards brand new so i can only assume this is normal?

d) Conroe throttling - I had overheating problems so this crossed my mind but as you're water cooled and don't have this problem it can't be that

e) Power supply - I have a 700w FSP PSU so it's unlikely to be this


As I said, no idea if any of these ideas carry any weight, if you manage to solve it let me know.

Sounds exactly the same problem m8. When your in this mode just try running 3D mark and looks at the FPS I bet its halfed. Try doing 3D Mark 06 from first boot and make a note of the FPS in Proxy.

I need to do some more testing but it looks like an overheating problem. I'm going to check with everest. I have asked the Nvidia drivers to reports any thresholds exceeded but so far I have had none reported. Very strange but depending on the game this problem might be happening a lot but people are not seeing it because even 1 card is still fast enough for most things.

 

[The Asgard]

I would say thats it's got nothing to do with the PSU,go into the conrol panel and make sure 3D Mark is set to "Single display performance mode" in the programs settings,as when you first install the driver it sets to "Multiple display performance mode" you find it set to this in all the games & benchmarks in the program settings as this seem's to be Nvidia's default setting.So what ever game or benchmark you use that has an SLI profile make sure you change it to "single display performance mode".
The other thing i have noticed is by using the classic control panel it seems half the SLI profiles are missing so if possible use the new control panel.

I tried that but it had no effect. Only way of getting out of this mode is a reboot. Default settings work fine until this borked mode kicks in.

 

[locutus12]

given all the 7950GX2 is is 2 X 7900GT`s bolted together in an ugly design and linked with an SLI connector bridge to allow them to run through one PCI-E socket, ... is it not possible that one of the boards is simply dead on arrival or at least faulty?

 

[The Asgard]

given all the 7950GX2 is is 2 X 7900GT`s bolted together in an ugly design and linked with an SLI connector bridge to allow them to run through one PCI-E socket, ... is it not possible that one of the boards is simply dead on arrival or at least faulty?

Possibly. One card could be faulty certainly some issue with mine. The one thing I don't like about Sli is you don't really know if its working. Especially with some games.

 

[w3bbo]

I had very similar problems.

The way I sorted it was to ensure I had 16x pciE lanes open in one slot. Before I only had 8 + 8. Drivercleaned and re-installed the latest official drivers and everything is now working as it should. I didn't need to mess with the multi GPU configuration, I didn't change anything in there. I went straight onto return to proxycon(3d06) and saw my fps jump to 65 - happy days

 

[The Asgard]

I had very similar problems.

The way I sorted it was to ensure I had 16x pciE lanes open in one slot. Before I only had 8 + 8.

How did you do that m8?

Did a fresh install today

 

[fobose]

I would have thought those options are in bios.

 

[w3bbo]

Yeah option in the bios but this is on a NF4 SLI-D..dunno if your conroe board will have that option.

Remember that this card will only work with a 16x pci-e slot as each GPU requires 8xlanes. Before I had 8x for each slot now I have 16x for the top PCIE slot and 1x for the bottom (not used).

Hope you get it sorted coz I want to know if the 7950gx2 works ok with all conroe 16x boards - due to upgrade soon.

 

[Coolasmoo]

The P5WDH he is using is 2 X 16 lanes and only changes to 2 x 8 when both slots are being used (crossfire)

There is nothing in the Bios that can be configured slot wise

 

[The Asgard]

Running some more test and a run at 3D Mark 2006 with Everest Logging

Overclocked 550/700

GPU1 °C Min 55 Max 80
GPU2 °C Min 64 Max 86

Compared to my X1900 under air they are slightly less

Still working fine.

 

[The Asgard]

Right its back in its borked state and I have just ran 3D mark 06 with everest running.

GPU1 °C Min 62 Max 80
GPU2 °C Min 67 Max 70

Looks like GPU2 is not working

 

[Morfik]

That looks pretty conclusive Asgard. The temps in the 1st instance weren't hot enough to cause it to slowdown the second GPU though - why is it doing it?

 

[The Asgard]

That looks pretty conclusive Asgard. The temps in the 1st instance weren't hot enough to cause it to slowdown the second GPU though - why is it doing it?

I have not got a clue.

If I force the driver back to single gpu and then back to sli it all starts working again. Something is causing the Sli to drop out.

Just checked the event log, nothing.

Just going to send the card back obviously there is a fault. Not sure what to do for a replacement now.