Microsoft’s DirectX 12 API features support for asymmetric multi-GPU setups as long as the cards support a consistent DX12 feature-level. Ryan Smith over at Anandtech put Microsoft’s claims to the test by running an AMD Radeon R9 Fury X and an NVIDIA GeForce GTX 980 Ti together on the same test system and ran some tests on Ashes of the Singularity.
He found that alternate-frame rendering (AFR) worked great for his mixed multi-GPU setups and that he was getting some solid performance increases that were once only obtainable by using paired cards with NVIDIA SLI or AMD CrossFire technology. No stability issues were found Ryan found that what card you use as the primary card matters and that it was best to use the AMD Radeon R9 Fury X as the primary card. His testing showed that the R9 Fury X + GTX 980 Ti is roughly 75% faster than a single R9 Fury X while GTX 980 Ti + R9 Fury X is 64% faster than a single GTX 980 Ti. Another interesting thing that he found was that the largest gains were from the mixed GPU setups and not from mixed and matched NVIDIA or AMD only test configurations.
This is pretty interesting information and it will be beneficial to see how discrete graphics cards do on a final DX12 game title. Stardocks Ashes of the Singularity multi-GPU tech demo is still in the alpha stages and we’ll take wait-and-see approach to see if this holds true in game titles in the years ahead!