ATI better positioned in race to unify shaders

Dis-unified Shading is a good approach and it will run DirectX 9 games fast for the months to come, but it won't much help developers, as these chaps have to prepare to write unified code.

It is a take-it-or-leave-it offer, as Microsoft requires them to use unified shaders from now on.

The Unified Shader concept pays dividends but at the same time it brings some additional troubles.

When you (over)load the Pixel Shader which is the case in most of the games to come, the vertex Shader comes for free. In this case you can tell your artists: Don't draw a normal map, please model it for me. This is how it works in DirectX 9 games.

Once the developers go to Unified Shader and DirectX 10, it is all going to change. When you load, or overload, the Vertex engine you automatically overload your pixels as well. And once it gets unified you cannot count pixel and vertex budgets separately, as it is all unified budget.

A 64 Unified Shader pipeline card can do any combination, including 32 pixel and 32 Shaders, 60 Shaders and 4 Vertex or 50 Vertex and 16 Shader information per clock, or any other combination that adds up to 64.

ATI is about to launch its second-generation Unified Shader hardware. While Nvidia seems to be lagging.

For its part, ATI claims that it managed to totally eliminate vertex to pixel switching overhead, a problem that the developers have been struggling with for a while. µ