Significant temperature difference between SLI cards

[runevirage]

Hi, I'm currently running two GTX 275 in SLI. Using EVGA precision, I measured the temps on both the graphics while playing Batman: AA today on max settings. GPU1 had temps up to 85 degrees Celsius whereas GPU2 had temps around 45-50, which is almost idle. SLI is enabled in the Nvidia control panel. I'm wondering if the my second GPU somehow isn't running? Or could someone explain the large temperature difference to me? Thanks.

 

[shadow187]

Check if the hotter GPU is the card on top. If it is, it's easily because the first (cooler) card is dumping its hot air on the second card.

 

[runevirage]

How do you check which one is which? Also, would it account for that great of a temp difference? Seems to me they shouldn't vary more than 10 degrees.

 

[Mousemonkey]

Have you enabled the SLi indicators to confirm that SLi is working in game?

 

[runevirage]

How do I do that?

 

[Mousemonkey]

Nv control panel > manage 3d settings > enable SLi indicators.

 

[shadow187]

No MouseMonkey, my logic is flawless. Hot air rises -> Card on top is hotter.

>_____________________________>

@OP.

Compare the FPS of games you play with the FPS of benchmarks. If FPS > Benchmark, then SLI works. If FPS < SLI_Benchmark, SLI doesn't work.

Simple, yes?

No?

Anyone!?

:c

 

[Mousemonkey]

No MouseMonkey, my logic is flawless. Hot air rises -> Card on top is hotter.

>_____________________________>

@OP.

Compare the FPS of games you play with the FPS of benchmarks. If FPS > Benchmark, then SLI works. If FPS < SLI_Benchmark, SLI doesn't work.

Simple, yes?

No?

Anyone!?

:c

No one is doubting your logic but going by those temps the bottom card is idling and the top card is doing all the work i.e SLi is not working.

 

[runevirage]

Nv control panel > manage 3d settings > enable SLi indicators.

I don't seem to have that in my Nv control panel. Is there another name for it?

Ok, so I did some benchmarks, these are games without and with SLI, followed by their temps in GPU1 and GPU2. Settings are 1920x1080, max settings, vsync on:

Street Fighter IV: 57.39 (85/50), 59.94 (85/65)
Dawn of War II: 46.76 (90/50), 68.08 (85/75)
Batman: Arkham Asylum: 47 (85/50), 44 (90/55)


The above results indicate to me that SLI isn't working in Batman, and confusingly, actually seems to hurt fps. Any suggestions?

 

[Mousemonkey]

If you cannot see something like this in the Nv control panel then you have a bigger issue to sort out first.

 

[runevirage]

If you cannot see something like this in the Nv control panel then you have a bigger issue to sort out first.
http://img687.imageshack.us/img687/5094/slin.jpg

Oh, there. I see it now, I've got a Physx indicator too. Where are they supposed to show up? In-game?

 

[Mousemonkey]

Yes, or just run 3d '06 or Vantage.

 

[runevirage]

Yes, or just run 3d '06 or Vantage.

Ok I just ran it on Batman: AA. There's a large vertical bar to the left, and it says "Physx+GPU" on top, and below that "SLI" and a green box next to it. Does this mean it's working?

I just re-ran the benchmark without and with SLI using the newest Nv drivers from a couple days ago. I'm still getting that a single GPU performs better than SLI. Either SLI's not working or the game is just terribly optimized for it.

 

[Mousemonkey]

If the bars are there when you are in game then SLi is enabled, but Batman AA is not all that, IMHO. Have you installed the latest SLi profile update?
http://www.nvidia.com/object/nvidia_multigpu_SLI_profile_update_v3.html

 

[runevirage]

If the bars are there when you are in game then SLi is enabled, but Batman AA is not all that, IMHO. Have you installed the latest SLi profile update?
http://www.nvidia.com/object/nvidia_multigpu_SLI_profile_update_v3.html

The games listed in that update are all DX9, and BMAA isn't included anyway. Also, the latest driver which was released just 2 days ago should include everything in it.

I guess the game is just not very optimized for SLI, which is a downpoint on a rather good experience. It's not like it runs horribly at 45fps anyway. Oh well. Thank you very much for your help, is there any way I can give you kudos?

 

[Mousemonkey]

It's always worth doing the SLi profile and PhysX updates separately as they are not part of the driver update, as for the kudos you can give me best answer if you wish but I'm only here for the fun of it mate.