Scott Michaud over at PCPer has written an analysis of the revelation that Vulkan Multi-GPU might be limited to Windows 10 due to Vulkan requiring WDDM linked display adapter support. Linked display adapter support is only found in Windows 10 as it requires WDDM 2.0. It seems that Windows 7 and 8 can receive mGPU support but only if the development teams are willing to do the heavy lifting. Unlinked Multi-GPU or what is commonly referred to as MDA under DX12 would support Multi-GPU under Vulkan. Remember when Oxide Games got Ashes of the Singularity to run AMD and Nvidia GPUs rendering the scenes together? This is the same type of technology but under Vulkan.
Will this make developers implement this technology more freely to make sure that they can cover users of many operating systems at once? Make sure to go check out this very interesting article by Scott Michaud as it has charts and much more detailed answers to these and other questions in his article. You can refer back to the original DSO Gaming article and comments from our readers here.
On the other hand, this limitation might pressure some developers to support unlinked multi-GPU configurations. There are some interesting possibilities, including post-processing, GPGPU tasks like AI visibility and physics, and so forth, which might be ignored in titles whose developers were seduced by the simplicity of device groups. On the whole, device groups was apparently a high-priority request by game developers, and its inclusion will lead to more multi-GPU content. Developers who can justify doing it themselves, though, now have another reason to bother re-inventing a few wheels.