Only in Windows 10, is of course used in the same way as "new CPU's will only work in Windows 10." In other words, Windows 10 is the only Windows OS to get mGPU support in Vulkan, due to this feature depending on WDDM 2.0, available in Windows 10 only. Linux and potentially other open source implementations should get it as well. Which begs the question, what is Microsoft doing to strong-arm these third parties into making Windows 10 only features? Also, if it will work on Linux as well, this obviously means Vulkan mGPU does not fully depend on WDDM2.0, as there is no WDDM at all in alternative operating systems. With Vulkan being Open Source, I wonder if it would be possible for someone to fork the code, and make a Vulkan version for Windows 7 and 8.1 using the Linux mGPU implementation. With how vocal and creative the anti Windows 10 crowd can be, it wouldn't surprise me if someone were to try. As the article suggests, this may be a moot point either way though, as mGPU in Vulkan and DirectX 12 require the implementation to be in the game, not in the API, and we all know how ambitious most game devs companies are when it comes to writing code. That being said, if commonly used game engines get this tech built in, maybe we will see it after all. "Now I don’t know whether there will be enough games supporting such a feature, especially since a lot of DX12 games (and I’m using DX12 as an example because more developers are currently using it) are still lacking multi-GPU support, but these few PC gamers with high-end multi-GPU systems will have to use Windows 10 in order to enjoy Vulkan’s multi-GPU support."