Intel Xe And Arc Graphics Lack DX9 Support Forcing DX12 Emulation
If you're a PC gamer, you are likely someone who likes to revisit old favorites. After all, one of the greatest benefits of PC gaming (versus game consoles) is the ability to freely go back and enjoy classic titles from ages past. Doing so may be clumsy on Intel's Arc GPUs, however, as it turns out that they don't natively support the DirectX 9 API but instead use an open-source translator called D3D9On12.
D3D9On12 is exactly what it sounds like: a translation layer that shims between the DirectX 9 game and the DirectX 12 API. Microsoft created it, and it is actually part of the Windows 10 operating system. Redmond decided to release the translator as open-source software because it feels that the layer has become "a complete and relatively performant implementation of a D3D9 driver," and it's looking for community contribution to the project.
Source: Intel
Clearly, it's complete and performant enough for Intel to rely on it entirely for DirectX 9 applications running on its graphics adapters. This information comes directly from Intel itself, by the way. The blue team published a support article titled "Which Intel Graphics Products Support DirectX 9 (DX9)?" You can see a screenshot of the whole article above.
The comical part of the support announcement is how Intel rather unashamedly passes the buck for any issues in DX9 games to Microsoft. The article clearly says "troubleshooting of DX9 apps and games issues require promoting any findings to Microsoft Support." It's true that problems in DX9 games could certainly be down to the D3D9On12 layer, but it's also rather clear that Microsoft is through working on it. Furthermore, there's no reason rendering issues in D3D9On12 couldn't be down to a bug in Intel's own graphics driver.
Of course, it's understandable that Intel's graphics driver team is overloaded just trying to get DirectX 11, DirectX 12, and Vulkan working properly—to say nothing of OpenGL support. Contrary to popular belief, Vulkan does not supersede or replace OpenGL in its entirety, and if Intel wants to fully support Windows software, then Arc is going to need quality OpenGL support, too.
Despite the majority of big AAA releases moving to DirectX 12, those aren't really the games people are playing for the most part. If we peek at the Steam player data, most of the top games going right now are based on DirectX 11. Intel probably thinks that DirectX 9 games are lightweight enough that the D3D9On12 translator will still provide sufficient performance, and that may indeed be the case. We'll just have to see when we do our own in-depth Arc testing.
