MojoKid writes "The PC demo for Codemasters' upcoming DirectX 11 racing title, Dirt 2, has just hit the web and is available for download. Dirt 2 is a highly-anticipated racing sim that also happens to feature leading-edge graphic effects. In addition to a DirectX 9 code path, Dirt 2 also utilizes a number of DirectX 11 features, like hardware-tessellated dynamic water, an animated crowd and dynamic cloth effects, in addition to DirectCompute 11-accelerated high-definition ambient occlusion (HADO), full floating-point high dynamic range (HDR) lighting, and full-screen resolution post processing. Performance-wise, DX11 didn't take its toll as much as you'd expect this early on in its adoption cycle."
Bit-tech also took a look at the graphical differences, arriving at this conclusion: "You'd need a seriously keen eye and brown paper envelope full of cash from one of the creators of Dirt 2
to notice any real difference between textures
in the two versions of DirectX."