For now, DirectX 11.1 will be a Windows 8 exclusive.
Microsoft's Daniel Moth revealed a few months back that DirectX 11.1 will be a Windows 8 exclusive – at least initially. The revelation arrived by way of the Microsoft Answers forum in response to questions about using the WARP accelerator and understanding the software stack C++ AMP is built upon.
"With DirectX 11.1, WARP was enhanced with (among other things) support for DirectCompute and hence it is one of the accelerators for C++ AMP. DirectX 11.1 is part of Windows 8, just like DirectX 11 was part of Windows 7," Moth answered.
Originally DirectX 11 was eventually made available on Windows Vista too, but for now Microsoft has no plans of doing the same and bringing DirectX 11.1 to Windows 7. "Should the plan change and either DirectX 11.1 as a whole, or WARP on its own, was made available on Windows 7, then you would have this available to target from C++ AMP," he added.
According to the post, WARP is a high speed, fully conformant software rasterizer. It's a component of the DirectX graphics technology that was introduced by the Direct3D 11 runtime. Moth describes it as a component of Windows 8 that can be shipped on other platforms, but currently there are no plans to do so.
One of Microsoft's big push with Windows 8 is in the platform's gaming capabilities. The Games app brings to the user front and center seemingly everything Xbox Live gamers have enjoyed for years. Games can be purchased for either platform, and achievements can be shared with friends and family spanning simple games like Solitaire to Call of Duty: Black Ops 2.
Making DirectX 11.1 exclusive to Windows 8 seemingly pushes PC game developers into embracing the updated platform if they want to utilize those features. Various developers have expressed their distaste for the built-in storefront, but now that we're weeks into the platform's release, there really doesn't appear to be anything to stress over. Gamers can still purchase their games from Steam, GameFly, GameStop and more as if they've never left the Windows 7 desktop.
To show what Windows 8 can do, we can only dream that Microsoft would green light a version of Halo 4 that takes advantage of DirectX 11.1 and the new Metro UI design.