If your graphics card doesn't support DirectX 10 or 10.1, don't worry about it, Microsoft has your back. The resourceful programmers at Redmond are working on a new component called WARP10 (Windows Advanced Rasterization Platform) to be included in Windows 7, which essentially ports DX10 duties to the CPU.
The upshot is that everyone will have access to DX10 eye candy even if the hardware doesn't support it. Minimum requirements for WARP10 are the same as they are for Vista - an 800MHz processor and 512MB of RAM. So if you have the hardware to run Windows 7, then in theory, you should be able to enable advanced effects regardless of your videocard.
"Our primary goal during WARP10 development was to produce a rasterizer that met or exceeded all the precision and conformance requirements of the Direct3D 10 and 10.1 specifications," writes Andy Glaister, Principal Development Lead of Microsoft Desktop and Graphics Technologies. "We wanted to do this while achieving a high level or reliability and stability. If this rasterizer was going to be used as a fallback for when hardware was not functioning, it’s important that it worked in all scenarios, configurations and different types of machines."
The downside is that everyone will have access to DX10 eye candy, even if the hardware doesn't support it. There's a potential for system vendors and resellers to mislead customers with DX10 marketing, even if the system being sold isn't up to the task. Running Crysis in DX10 mode at just 800x600 with everything set to low, Microsoft benched a Core i7 at 3.0GHz averaging just 7fps. By contrast, the same benchmark pulled an average of 5fps using an Intel integrated DX10 video solution. On an ATI 2400 Pro, that number jumped to 30fps. In short, WARP10 provides minimal gains over integrated graphics, and gets trounced by budget discrete GPUs.
To be fair, Microsoft isn't pitching WARP10 as a replacement for graphics, nor is the company saying DX10 should be rendered on the CPU instead of the GPU. When it comes to gaming, Microsoft sees its rasterizer being used as a diagnostic tool to help developers validate any visual artifacts as being rendering errors or problems with the hardware or drivers.