Microsoft's DirectX 12 Enables Intel, AMD, Nvidia GPUs To Work Together

Remember that tantalizing rumor about Microsoft's DirectX 12 enabling AMD and Nvidia video cards to work together in sweet, pixel-pumping harmony? It turns out it was kind of true. A feature called "Multiadapter" will allow integrated and dedicated graphics solutions to work together in DirectX 12-coded games.

Just about every desktop or notebook PC that ships contains an integrated GPU -- that is, an embedded graphics solution contained within the CPU. Intel has their Intel HD and Intel Iris graphics, and an increasingly popular CPU option from AMD is their APU, an "Accelerated Processing Unit" that contains a lower-tier Radeon GPU.

These integrated graphics chips are capable of running the world's most popular but less graphically demanding games -- stuff like League of Legends, DotA 2, and Hearthstone -- but not every game. Not by a longshot. Which is why most gamers choose to install a dedicated (or "discrete") graphics card from Nvidia or AMD. But when that happens, the integrated graphics capabilities of your CPU all but fade from existence.

Microsoft's Multiadapter in DirectX 12 takes aim at that problem, effectively making your integrated GPU useful again, and contributing to the post-processing workload. Which is, quite frankly, awesome since post-processing has a genuine impact on framerate and overall performance.

Microsoft's Andrew Yeung explains: "Virtually every game out there makes use of postprocessing to make your favorite games visually impressive; but that postprocessing work doesn’t come free. By offloading some of the postprocessing work to a second GPU, the first GPU is freed up to start on the next frame before it would have otherwise been able to improving your overall framerate."

In their testing, they used an Unreal Engine benchmark to pit two systems -- one with a dedicated Nvidia GPU, one with a dedicated Nvidia GPU + an Intel Integrated HD Graphics solution -- against each other in a race to render 635 frames. The Multiadapter system won, and delivered an average 39.7fps versus the single GPU's 35.9fps. That may seem insignificant, but consider this: That's a 10% performance gain for free. And there's more good news: Microsoft says that during these tests, the Intel GPU was only being 70% utilized. "Looking to the future, this tells us that the opportunity exists to extract even more performance out of the demo hardware," Yeung says.

We've seen how simple driver updates can improve performance, so this is a very promising development.

While it's highly unlikely we'll see mixed dedicated graphics cards -- like an Nvidia GTX 760 and an AMD Radeon 285 -- working in harmony under DirectX 12, you can see where the source of that original rumor was derived from.

In theory, this means you will see AMD APUs working in tandem with dedicated Nvidia GPUs. While AMD has already implemented CrossFire capabilities between their APUs and a limited selection of dedicated Radeon cards, this blows the door wide open for developers to tap into the full potential of a gamer's hardware. Let's hope they do.