Does VorpX Support SLi?

[RAGEdemon]

Seeing as the ideal resolution of the Vicve / Rift / Vorpx is “1920×1440” and higher, is there SLi or crossfire support, seeing as that VorpX itself is doing the dual rendering in Stereo3D. For comparison, both 3D Vision and I believe the old iZ3D driver support SLi, and it scales extremely well.

For most games, even a single GTx 1080, the single fastest graphics card in the world does not support 90fps at 1920×1440, let alone geometry 3D which has a 2x performance hit.

If not, are there plans in the future?

Thanks.

[Ralf]

There might be some options for utilizing a second graphics card in the future, but classical SLI probably never will work. Normally the graphics driver outputs the final image to the monitor in SLI mode, vorpX however has to feed the final image to the headset, which makes the whole process *very* different from normal monitor rendering.

[Fredthehound]

OK I am confused. Can you clarify this for me?

On Skyrim, I see massive activity on both cards on my Crossfire rig. When I shut one card down, I fall -to- 7-12 FPS in geometry mode (heavily modded Skyrim)

I am assuming you mean that VorpX ‘in and of itself’ is not ‘also’ using SLI/Crossfire rendering? In other words, the Games still use Crossfire/SLI to do their thing before VorpX does what it does, but VorpX is processing on one card?

[Ralf]

vorpX itself is agnostic of SLI/Crossfire. Since it hooks into the rendering pipeline you should always expect the possibility of issues though. If that isn’t the case for you, there is no need to disable it, but there is no guarantee that it works correctly.

[Fredthehound]

Thanks Ralf, Thats what I thought but wanted to be sure as I’ve told people on the Vive board that Crossfire works. In my case, pretty well.

So far I have gotten a fairly stable/enjoyable experience once getting my settings where I like them. Power hungry, but it’s the nature of the beast.

I’d also recommend people look up the “Z Fighting” vids Gopher did on Youtube if they are getting flickering on clouds/fog in Bethesda games. Those help a lot.

[RAGEdemon]

Hi,

Now I’m confused.

I have tried games such as Portal 2 and Mas Effect 3. All of which work flawlessly in SLi when VorpX is not running. With VorpX enabled, there is virtually no activity on the second card.

If indeed the game can render with both cards simultaneously and increase their performance, then I think that is something huge that needs to be looked into.

Perhaps it’s a case of Crossfire working but SLi not?

[Fredthehound]

All I know for sure is that using both MSI Afterburner and Skyrom Performance monitor with AMD Crossfire, I have activity on both cards. And enough activity that I had to water cool them both to deal with the heat pushing them full up was generating.

IT could be AMD vs Nvidia thing. Perhaps on a profile level. With AMD, there are multiple styles of “Crossfire” different games use. AFR / Optimize 1-1/ and AFR comparable.

[Fredthehound]

Just noticed you are on Rift. I’m on Vive. Could be something there as well.

[RAGEdemon]

Oculus have coded SLi/crossfire to be disabled because they claim it causes “lag”. I wish there was a way to bypass this arbitrary limit. I assumed it was the same with the Vive? Can you get normal VR games to work in crossfire too? I cant with Oculus. I was hoping that Vorpx did something to lift this limit with you.

Do you notice lag in head tracking? I feel doubling lag would be worth doubling the performance.

Ralf, does VorpX really require Oculus runtime to be running?

Thanks.

[Fredthehound]

The VR games I have arent coded for SLI/Cross. My understanding is so far none are.

[Fredthehound]

Head Tracking. No, my head tracking seems fine. Nothing seems laggy unless I set the sensitivity down. Controllers are 1-1. First time I actually saw them in VR, I forgot I was seeing the VR version and not the real ones ;)

[RAGEdemon]

Most games are indeed not coded for crossfire or SLi, but you can use the VR game engine as a good indicator, for example, if it uses Unity, UE4 etc. then you can use a profile from a non VR game using the same engine to see if it works. If HTC haven’t blocked it in some manner, it should work just fine.

For example, on the old oculus runtimes, SLi ran without problems.

It would be a cool test to do, if you have the time :)

I’m biased of course, i’m desperate to get SLi working, for obvious reasons. Then I can SLi 1080s for a hopeful 90fps @ ~1920×1440 – what our VR headsets were designed for!

[Ralf]

@ RAGEdemon: No way around the Oculus runtime. Without it it’s impossible to render to the Rift. You can imagine that similar to a DirectX game not working without the DirectX runtime being available.

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