Can you run Half-Life: Alyx in SLI?

Dash Lambda · April 2, 2020

I should probably start off by saying that I'm well aware of the state of SLI. I have dual cards for totally different reasons (mostly 4+ monitors and unobtrusive background GPGPU tasks), they weren't even the same chip until about a month ago. I do not recommend that anyone intentionally build an SLI system unless they're already getting the best single cards on the market, much less for VR.

But I have these cards, and I like to tinker. I've already tried just enabling SLI and running the game, and while it runs, it still only runs on one card. Frankly, given my limited prior experience with SLI, the fact that it runs at all is surprising. But I'd love to be able to throw both cards at it. I haven't been able to find anything so far except speculation about VR SLI support from months ago, but that obviously isn't supported. Has anyone gotten it to work?

PlayStation 2 · April 2, 2020

As far as I know, Source 2 doesn't really have multi-GPU support; as far as I remember, neither does Source or Goldsrc, so it's likely something Valve doesn't deal with.

If it sounds like I'm not answering the question, sorry; finding out if Source (and Source 2) supports multi-GPU setups (like SLI) is not the easiest feat, but as far as I can tell, Half-Life: Alyx most likely doesn't support it.