SLI for VR

[Jade_Monkey]

Hi everyone,

 

I was just wondering if anyone got SLI or even Crossfire to work with VR.

 

Right now my second card is not being used despite the multigpu being enabled.

 

Cheers!

 

-JM

[mga]

There is probably less than 5 games that work with SLI in VR, one of them being Nvidia Funhouse, so I wouldn't hold my breath.

[Mars27]

Interested in this myself as I have a gtx690 and not quite ready to buy a new card and a VR headset.

 

Could be Nvidia have pulled a crafty one and disabled it in the latest drivers as suggested by this post on Elite Dangerous and SLI:

 

https://www.reddit.com/r/oculus/comments/41ui09/windows_10_sli_dk2_and_elite_dangerous/

 

 

I've been struggling for months now to get Elite working in VR again on windows 10. I've finally found a way that works that some might find acceptable/useful.

Essentially the problems for me began when windows switched from it's WDDM 1.3 to WDDM 2.0 which gives access to the (forthcoming) features of DX12. Upgrading to the WDDM 2.0 enabled driver sets has broken rift usage for me in windows 10 whilst using SLI.

A lot of people seem to think SLI doesn't work with the rift - but for me its the difference between mostly stable when active 75fps and not anywhere near that when switched off. I honestly don't notice any latency and this is in a 3 way 760 SLI setup. (I won the third card in a competition - with some poetry I might add! - before you flame me for the build xD)

I struggled in vain for ages trying to get the runtime switcher to work but even when it switched to 0.5 (steamvr doesn't support/use SLI for me) it would crash my PC. I literally thought I had a hardware issue with my GPUs.

However today it dawned on me the problems began with the DX12 driver branch so I went back and re-installed 347.88 enabled the runtime switcher to 0.5 and now SLI functionality has returned and works flawlessly!

I realise this won't be an acceptable solution for some who need the most up to date drivers for more recent games but I really only play Elite in VR and DOTA 2. So I'm super happy! :D

Edited April 15, 2017 by SYN_Mars

[mga]

Could be Nvidia have pulled a crafty one and disabled it in the latest drivers as suggested by this post on Elite Dangerous and SLI:

 

I doubt it. From what I know VR SLI is an API that needs to be implemented.

[Mars27]

I was referring to 'normal' SLI not VR SLI as they are two different things

 

You are correct about VR SLI needing to be implemented in th engine

[mga]

I was referring to 'normal' SLI not VR SLI as they are two different things

 

Ohh, I didn't realize that. The SLI support is there but it currently has a few bugs (either stuttering or terrain flickering, depending if you enable AFR or AFR2). NVidia should update the relevant bits for it to work again.

[=TBAS=Sshadow14]

Anything under GTX 960 is not VR Compatible so even with SLI working you cannot run VR.

The drivers will not let you

Edited April 17, 2017 by =R4T=Sshadow14

[Jade_Monkey]

I wanted to get rid of SLI before this but now I am convinced. 

If anyone is looking for a cheap second hand GTX 980ti (or two of them) PM me.

[mga]

I wanted to get rid of SLI before this but now I am convinced. 

If anyone is looking for a cheap second hand GTX 980ti (or two of them) PM me.

That's what I did as well. BOS was one of the very few games supporting SLI so I just sold one of my 980ti's after SLI didn't work anymore. I am just waiting for the aorus 1080 ti now ...

[Mars27]

Update:

 

I received my pimax4k last week and discovered that SLI does indeed work on older drivers:

 

Of the drivers I have on my PC, SLi works with version 362.00 and earlier but does not work with the more recent 378.78.

 

This holds true in Il-2:BoX and Elite Dangerous.

[MajorDogbite]

As indicated above, VR-SLI requires it be coded into a game and also would require dx12 and thus Windows 10.There is

apparently partial support in dx11 but I am not sure to what extent. As for normal sli itself, this is not currently

supported in VR. There have been people report that they got it working in Elite Dangerous, however, none have been able to prove an improvement in performance with this, only that sli didn't interfere with running the game. In most cases

that I have read, people were complaining of sli causing issues while running in vr while it is enabled.

Edited May 16, 2017 by MajorDogbite