Myth busted: Vulkan's multi-GPU support isn't limited to Windows 10

Don't believe everything you read on the Internet.

evga quick disconnect water cooling
Brad Chacos

The whole appeal behind the next-gen Vulkan graphics API is that it’s wide-open and cross-platform. Vulkan offers many of the same “close to the metal” capabilities as Windows 10’s DirectX 12, but unlike Microsoft’s graphics tech, Vulkan also works on Linux, older versions of Windows, and even Android devices.

So when reports surfaced last week that Vulkan’s multi-GPU support was limited to Windows 10 alone, it understandably raised a ruckus in PC-centric forums and subreddits across the web. That caused even more websites to cover the issue, which led to even more angst on forums, which led to… well, you get the idea.

Calm down. It’s not true, as the Khronos Group that oversees Vulkan explained in a recent post.

“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.”

The slide that begat this brouhaha referred to implementing Vulkan specifically on Windows, the Khronos Group explained. Implementing Vulkan on other operating systems obviously wouldn’t require Microsoft’s WDDM. The initial reports pointed to the LDA mode as a smoking gun. The Khronos post refutes that: While LDA makes implementing Vulkan easier on Windows, it isn’t “strictly necessary,” Khronos said.

Khronos also clarified that LDA mode works with multiple versions of Windows, not just Windows 10 as some sites reported. “If an implementation on Windows does decide to use LDA mode, it is NOT tied to Windows 10," Khronos explained. "LDA mode has been available on many versions of Windows, including Windows 7 and 8.X.” 

So there you go. Vulkan support for multiple graphics cards will extend beyond Windows 10. Myth busted, Star Citizen vindicated. And as a juicy tease, Khronos says it’s aware of products with multi-GPU support coming to non-Windows 10 platforms—including Linux.

To comment on this article and other PCWorld content, visit our Facebook page or our Twitter feed.
Shop Tech Products at Amazon