How well is SLI performing following the recent updates? (Particularly with the Vive)

I’m a firefighter/paramedic and I’ve been working on a simulator for my industry for sometime. I’m approaching the point in development where it is time to spec out an actual machine to run the simulator on. Mainly, I’m looking to decide if my simulator build should have SLI. I will be taking the machine to various customers and running their staff through them so performance needs to be the best they have ever seen.

For the past two years or so, the answer has been a “pretty much no”. However I know in September the VRworks update added SLI compatibility to VR in the Unreal engine. I’m looking to find out just how reliable it is and what if any incremental performance value there is to it.

The other question is overclocking and VR-- I’ve been mainly on a gaming laptop because I’m mobile primarily so my OC experience has been limited but I my initial thoughts are that there shouldn’t be much of an issue. Mainly it would be a temperature concern, not a depth or frame pacing issue, but then again, I don’t really know.

In order to get the best possible performance for your sim I’d suggest looking into VRWorks recent branch for 4.14. Got SLI, Lens Matched Shading and tons of performance solutions you’d need. You need to bare in mind that even if you’d go with VRWorks there’s still ton of optimization to be done in actual app/game/sim. From my experience, even with 1080, if you get carried away too much, you’ll lose that performance anyway. I know for a fact that Forward Rendering, which is in stock engine versions boosts up your performance significantly (aprox 20% and that’s for Epic guys working on Robo Recall), however compared to deffered rendering it has less options.

As for the numbers behind SLIs performance I’d yet need to test it myself, for the time being I’m happy with the results working on 1080.

So, would you recommend SLI 1080’s at this point, or just a single?

To tell the truth, personally I’d go with single. Especially that NVIDIA just announced 1080 Ti which is around 35% faster than 1080.

Just saw that… Now I have to decide to get a cheaper 1080 now or a TI when they ship

There won’t be anything better than 1080 Ti for quite some time now so if you’re willing to buy 1080 and can top up to Ti I’d do that if I were you :wink:

Or wait and see about AMD’s Vega…