DirectX 10 on CPU via DirectX 11 - first benchmarks
In an MSDN article Microsoft introduces WARP10, a software rasterisation platform for enabling DirectX 10 graphics on CPUs with DirectX 11. Rumors that DirectX 9 graphics cards will run DirectX 10 games seem to be a misinterpretation.
WARP10 stands for Windows Advanced Rasterization Platform and is part of DirectX 11, which is supposed to be released alongside the Windows 7 launch. Basically WARP10 is about non-DX10 compliant hardware (especially multi-core CPUs) rendering/accelerating DirectX 10 applications. So for example CPUs are able to accelerate DirectX 10 games.
WARP10 also supports DirectX 10.0 as well as DirectX 10.1. DirectX 11 games can also be emulated via fallbacks to DirectX 9 or DirectX 10 level. Even optional texture formats, anti-aliasing up to 8x, anisotropic filtering as well as 32 and 64 bit applications are supported. As minimal requirements Microsoft specifies a CPU with 800 MHz and 512 MiByte RAM - MMX, SSE or SSE2 aren't compulsory, but especially SSE2 and SSE 4.1 are supposed to deliver additional performance. WARP10 runs independently from the graphics card.
The biggest difference to the hitherto used software rasterizer seems to be that WARP10 makes intensive use of multi-core CPUs. The best performance is supposed to be obtained on quad-core CPUs. Furthermore WARP10 seems to run notably faster with SSE 4.1. Microsoft thinks during the life cycle of Windows 7 CPUs with eight or more cores will become quite common. in this instance Microsoft probably is referring to quad-cores with SMT like the Core i7.
Microsoft even offers Crysis benchmarks in 800 x 600 in Direct3D 10 mode with minimal game details. The results reveal that the CPU plus WARP10 can compete with Intel integrated graphics. Of course the fps rates are unplayable nevertheless, but the results can be seen as improvement. Microsoft also doesn't see WARP10 as a replacement for the graphics card.
If you want to take a closer look at WARP10 then you can read all about it in the MSDN article Windows Advanced Rasterization Platform (WARP) In-Depth Guide.
DirectX10 on DirectX9 graphics cards? Yes and No
The rumors according to which a DirectX 9 graphics card could be used on Windows 7 to run DirectX10 games have to be taken with a pinch of salt though: The DirectX enhancement "Direct3D10Level9” is only intended to make code management for developers easier. For this purpose three tech levels are defined, which replace the inflated Caps based model of the "real” DirectX 9 - the hardware still runs DX9 code based on the particular tech level, but can be addressed via the DirectX 10 API instead of requiring a full D3D9 code path.
CPU-Roadmap 2016 - 2018: Künftige AMD- und Intel-CPUs/-APUs in der Übersicht [Oktober 2016]