Yes, Dolphin Certainly Can Leverage Multiple GPUs (SLI, CrosFire)

So, I was testing out whether or not Dolphin can leverage my SLI setup, so I can run Dolphin at playable framerate (essentially locked framerate for whatever game I'm running, or higher using framerate patches for specific games), and was able to get SLI scaling in Dolphin and it does indeed work, but there are some graphical glitches, some potentially game-breaking, and can require the use of settings in the graphics options in Dolphin that may not be ideal, but are practically required to achieve scaling across multiple GPUs. This also only works with DX11, or if you have an older version of Dolphin, DX9 or DX10. I can play with 8X IR + 8X SSAA + FXAA + Asynchronous Ubershaders, and get a playable framerate for the most part; with 8X IR + 8X MSAA/2X SSAA + Synchronous Ubershaders, I can get a playable framerate with SLI most of the time. Also, I'm getting near-perfect 100% scaling across all the GPUs in my system.

Here's visual proof of Dolphin scaling with SLI (if available, choose original setting for highest quality viewing):

             Star Fox Assault: Video showing impact of settings in realtime with SLI enabled

               Luigi's Mansion: Video showing general scaling with very high graphical settings (8X IR + 8X SSAA + FXAA + Asynchronous Ubershaders, IIRC; unlimited speed setting)

       Star Fox Adventures:

                               Single-GPU:


                                 Multi-GPU:


                            Settings used for Star Fox Adventures:

(I'd advise against using GPU texture decoding, it tends to cause tons jank graphical glitches, especially with multi-GPU enabled and doesn't really add to performance)


If anyone with SLI or CrossFire(X) setups can replicate these results, please do tell.