The latest patch for World of Warcraft: Battle for Azeroth, version 8.1.5, includes the user-mode components of the Direct3D 12 (D3D12) runtime, modified to run on Windows 7. Blizzard found that there was a “substantial framerate improvement” from updating WoW to use D3D12, thanks to D3D12’s improved support for distributing the work of building graphical scenes across multiple threads. For complex environments with lots of on-screen objects, this multithreading can provide a healthy performance boost.
Microsoft insists that Windows 10 remains the best place to run D3D12 applications. This is probably true, as the company has continued to update the driver model and D3D stack to reduce the amount of “stuff” between high-performance graphical applications and the underlying hardware, increase the range of operations that can be performed in multiple threads, improve the programmability of GPUs (especially for computation tasks), and enable new hardware features such as the accelerated raytracing in Nvidia’s latest hardware. However, it’s also been clear that none of these changes are absolutely essential to having most parts of D3D12 on Windows 7. After all, the Vulkan API, successor to OpenGL, is available on Windows 7, using Windows 7 video drivers, and it offers many of the same multithreading benefits as D3D12.