It’s been a while and I prepared a lot of slides for DX12
but generally the constraints imposed by WDDM 1.1 still apply to all low-level GPU hardware abstractions on Windows 7. In the end the Win7/WDDM 1.1 system design & policies around GPU memory management & scheduling constrain the type of application and user scenarios that low-level APIs can be successful driving on that platform. It works decent for 1-2 high resource consuming applications at a time, but the user experience does not degrade gracefully if a lot of apps running simultaneously start loading up the GPU with low-level API usage on Windows 7. That does mean there’s a number of AAA games & engines that benefit from it though. Workstation apps are another category where the user tends to run just 1 high resource consuming app at a time, but users in that category tend to go for more recent OSs as that’s where the official support channels are greatest.
Why D3D12 on Win7? We’re at the next stage for D3D12 and low-level APIs in the technology adoption curve by developers and publishers. The next order of magnitude in the title & engine population are now designing first, or *only* for low-level APIs. The devs & publishers are making a lot of tradeoffs as part of this process:
- How do they get the most fidelity, frame rate, and functionality out of the low-level API for each target platform?
- How do they reward gamers who bought high end hardware with commensurate high end experiences?
- How do they get the largest total addressable market?
- Widest variety of hardware
- On all the OS and device platforms where the gamers are
- While keeping the engineering cost within budget
There’s a measurable population of gamers in some markets that likely won’t get off of Windows 7 in time for this next wave of titles and engines on low-level APIs. D3D12 on Windows 7 is what my team did to assist developers & publishers with the engineering cost and addressable market tradeoffs they were making. Developers get to focus more time/spend less effort on making their engines & titles work better on D3D12, publishers have a reduced cost for reaching their market on Windows, gamers who are stuck on Windows 7 still get to play the games with the limits imposed by that OS, and Windows 10 gamers get a larger number of games that can more fully exploit their hardware. All together it was a solution my team was really happy to make possible.
The system constraints in Windows 7, as well as the well aged properties of the ecosystem (just think of all the random drivers & software hooking into bizarre internal methods that were never designed to be touched outside of OS code), are why we’re doing a title by title rollout at first. We need to make sure the experience is a quality one across users, developers, and publishers.
Max McMullen
Development Manager
Compute, Graphics, and AI (yes, we chose the group name in that order because the acronym was funny to us)
Microsoft
