SLI, can't for the life of me get it to work

[Smeghead_3]

Just last week I purchased another GTX680, Ive spent the last few days going through all my games and finding out which work better with SLI and which dont.

IL2 COD is the only one in which I've had no success, it simply refuses to even attempt SLI.
I am computer literate and have been using nvidia inspector since I got my first 680 a year ago.

I followed the instructions here
http://forum.1cpublishing.eu/showthread.php?t=37316

but SLI doesn't seem to attempt to run.
Ive also tried creating custom profiles as I've had to do with other games but no success. I wouldn't mind so much if it ran SLI but not very well, but it just doesn't even attempt to run.
Hopefully I am missing something obvious but just can't see it.

any help appreciated

thank you


system specs:

sabertooth z77, i7 3770k@4.7, 2xgtx680, pcie xfi titanium
Windows 7 64
running nvidia 320.18 drivers
5960x1080 triple screen through nvidia surround

[RickRuski]

Hi Smeghead,

I will try to help you get it running if I can. Are you using the on screen information display that comes with EVGA Precision? if not download the tool from EVGA (it's free) and install it.
Make sure it runs with C.o.D. (it includes Riva Tuner )
If you select the correct loadings you will be able to see what is happening with your cards.

I would expect to see the card temps within a couple of degrees of each other (probably lower than just one card was reading) and the usage percentage demand varying between the two cards. The ram usage should be about the same for both cards.
I have not overclock my cards,( run at stock settings) and limit fps to 36 (this can all be done with EVGA Precision Controller. MSI has a similar tool).
Does the Cliffs of Dover profile show in your Nvidia Inspector? it should if you have installed the code correctly.

Have both your cards got the same amount of V/ram?? they must both be the same V/ram for Sli to work

[Smeghead_3]

Ok, RickRuski thank you for taking the time to help.
Your suggestion of using precision has lead to a few discoveries.

I monitored both GPU's whilst running COD and both were at 99%, but no SLI indicator was present. I thought great it's working but the SLI overlay isn't showing up.
I tried a few other games that work well with SLI and discovered that with SLI enabled both GPU's were in the 80-85% range. But if I disabled SLI (in inspector) then both GPU's were at 99%. If i completely dissabled SLI in the control panel then GPU behaviour was as expected ie 99%, 3-5%.
It seems that setting SLI rendering mode to force single in inspector , whilst in surround mode, is not the same as disabling SLI. SLI rendering is disabled but both cards still run flat out, no idea what the second card is really doing though.

But with 2 graphic cards disabling SLI in the control panel also disables surround, must be because you have to have monitors on both cards.

Long story short, whilst testing all this out I ran COD with surround disabled and SLI worked fine.

So I can run with surround off and SLI on or nice 3 screen surround and SLI off.

Haven't had this issue with any other game but with COD development at an end it seems that it wont be fixed, unless of course you know how to enable SLI in COD whilst nvidia surround is enabled ?
I might try messing about in inspector, now that I know that the profile is definitely working

thanks again,

[RickRuski]

Hi Smeghead,

The best suggestion I can make for you seeing that the problem seems to relate to multi monitor setup is go to the Nvidia forum and seek some help there. You will have to register to post there but they have a lot of very knowledgeable people that can help. I only use a single monitor hence single display mode selected (in the common section of inspector), have you tried setting this to multi display mode?. In the Sli section I have selected "Force AFR" (alternate frame rendering). I will also make some inquiries at Nvidia forums and see what I can find out.

Here's a section from the Nvidia forum relating to multi monitors: -

https://forums.geforce.com/default/topic/532913/nvidia-sli-technology-a-canine-39-s-guide/

[Quote]
•Multi-Display/Mixed-GPU Acceleration: This is to ensure compatibility with single or multi-monitor configurations. When using a single monitor, this should be set as "Single Display Performance Mode" unless significant visual artifacting (unrelated to GPU overclocking or overheating) is seen, in which case "Compatibility Performance Mode" should be selected instead. If using more than one monitor, this ought to be set at "Multiple monitor Performance Mode." If you notice artifacting on a multi-display setup, you may select the compatibility mode to remedy the situation.
[End Quote]

Remember that Cliffs of Dover has never had any official support from Nvidia for Sli (although there have been requests at Nvidia for it), the only thing has been Ilya's (Luthier) code that he supplied prior to the development being abandoned.

Check here: -

https://forums.geforce.com/default/board/50/sli/

and here: -

https://forums.geforce.com/default/topic/469402/sli/faq-quot-will-these-two-cards-work-in-sli-quot-sli-what-works-with-what-/

Here's a thread at Nvidia which throws some light on the problem, Nvidia are aware of it and hope to have a fix for it soon: -

https://forums.geforce.com/default/topic/546214/sli/can-t-enable-sli-with-nvidia-surround/

Cheers

Rick

[Smeghead_3]

awesome, thanks for the info, I just signed up to the geforce forum, looks like a pretty informative place.
Will probably be the weekend before I van have a muck about trying different inspector setting, multi display was set by default, tried changing to single but no difference.

had a look at the thread about trouble with SLI and surround, my issue isn't quite so bad, it works for me in all other games that I normally played in surround (iRacing,rFactor 2, ARM 2, etc) even il2 1946 runs great at 5960x1080 with SLI running, its just COD that wont, hopefully it could just be some inspector settings that will help.

Thanks again