SLI running slow?

[turtle1]

I have recently upgraded to SLI (2x BFG 8800GTX OC cards) and am getting a 3DMark06 score of 14636 with a e6850 oc'ed to 3.3Ghz. See signature. My old score on one BFG was around 12k. I have the most recent nVidia driver and have SLI selected in the nVidia control panel. Am I missing something?

I have the cards in PCI-e slot 1 and slot 2 on the Striker Extreme. Should I put them in slots 1 and 3?

Will admit that Crysis runs well.

Thoughts?

 

[Xazax310]

Seems about right getting a second card does magically double your 3dmark score, but in game and on Higher resolutions you will certianly see an improvement

(BTW im running two 8800GS in SLI)

 

[pauldh]

Yup, you won't get big gains in 3dmark06 at default settings with SLI. Like you said, Crysis you will see a difference.

 

[turtle1]

Thanks. What about the cards being in slot 1 and 2 right next to each other. Will they run cooler in slots 1 and 3 with more space bewteen them?

 

[turtle1]

5 minutes after exiting Crysis, GPU 1 is down to 56 degrees but GPU 2 is still at 76 degrees accrding to nVidia Monitor. Again, will moving the second card from slot 2 to slot 3 improve cooling?

 

[tjoepie]

I don't know the board but I think you also have to think that not all the Pcie have the same specs. Take the 2 fastest...

 

[turtle1]

I investigated the mobo on the Asus website and determined that the vid cards should be in slots 1 and 3 (blue PCIe slots) as they are the 16x slots. The center slot is an 8x slot. Still one of the cards runs 10 degrees hotter than the other... Not sure why..
Another question, in 3DMark system details it say shows 1 of 1 video cards and says, "linked display adaptors=false". Why would it say that running in SLI mode?

SLI is set in the nVidia control panel and Windows shows both cards running properly.

I just want to make sure I am getting maximum performance from these cards. Am I missing something?

 

[pauldh]

With my tight Sonata II case, my bottom 8800GT ran 8-10 degrees cooler than the top card. But after putting Zalman VF900's on them it's only 2-3 degrees difference. I suspect airflow and having a hot GPU below it to be the reason my top card is hotter. Not sure why your bottom is seeing higher temps. i would swap the two cards. if the top card is again the hotter one, don't sweat it or add better airflow around it. But if now the bottom card is hotter, the heatsink may not be installed as clean and secure on the card that runs hot.

 

[turtle1]

Thanks pauldh. I will try swapping the cards tonight and see if there is a difference. What is an acceptable high temp for the card to run at? Should I be worried at 79 degrees under heavy load?

I am sure the case I have provides good airflow and with the fan that is blowing accross the vid cards I am pretty sure that is not the problem.

I suspect you are correct, a heatsink issue and will verify with the card swap tonight. How hard is it to remove and reattach the heatsink to the vid card?

 

[LukeBird]

79C under heavy load with a GTX is fine.
My two cards hit rather different temperatures, one is about 45C at idle and the other about 58C, I think it's just how close they are, but I'm not particularly worried

 

[turtle1]

Thanks LukeBird. I still wish it was cooler running. Interesting that your GTX's run so much cooler than mine do... (right now at minimal load mine are at 54 and 67 degrees according to nVidia Monitor).

 

[turtle1]

Is it difficult to detach and reapply a heatsink to a video card?

 

[pauldh]

I'm not sure on the GTX. Hopefully someone who has removed the stock fan and reinstalled it can answer you.

The 8800GT is simple to remove, but there is one problem. It needs the thick thermal pads over the mem chips and mosfets left in place to make contact with the heatsink again.

 

[turtle1]

Thanks. I will try changing the cards around tonight first and see if that makes a difference.