At GDC 2017, in San Francisco during February, Khronos™ released several new Vulkan® extensions for cross-platform Virtual Reality rendering and multiple GPU access. This functionality has been initially released as KHX extensions to enable feedback from the developer community before being incorporated into final specifications.
The good news is that the Vulkan multi-GPU specification is very definitely NOT tied to Windows 10. It is possible to implement the Vulkan multi-GPU extension on any desktop OS including Windows 7, 8.X and 10 and Linux.
Some of the Khronos GDC presentations mentioned that for Vulkan multi-GPU functionality, Windows Display Driver Model (WDDM) must be in Linked Display Adapter (LDA) mode. That was not a very clear statement that has caused some confusion. And so it is worth clarifying that:
- The use of WDDM is referring to the use of Vulkan multi-GPU functionality on Windows. On other OS, WDDM is not necessary to implement the Vulkan multi-GPU extension.
- On Windows, the use of LDA mode can make implementing Vulkan multi-GPU functionality easier, and will probably be used by most implementations, but it is not strictly necessary.
- If an implementation on Windows does decide to use LDA mode, it is NOT tied to Windows 10. LDA mode has been available on many versions of Windows, including Windows 7 and 8.X.
Khronos always strives to make its specifications as cross platform as possible. Of course, what products ship on which OS is up to the implementers of each specification, but Khronos is already aware of vendor plans to ship multi-GPU functionality on platforms other than Windows 10, including Linux.