Direct 3D Benchmark: Expendable Timedemo
The chart contains two graphs each: The yellow is the standard benchmark result as we always get it, the green is the result with on-board sound enabled. As you can see, a PCI sound chip is absolutely no help in terms of performance. E.g. the Gigabyte board comes with a Creative chip, but the game performance is not clearly better than with the AC97 solutions of most competitors. The Asus board does not have a sound system, that's why the blue graph is missing.
Even though the Shuttle is slowest and the Asus the fastest; the differences are far too small to even talk about.
OpenGL Gaming Benchmark: Quake III Arena
Again we find very small performance differences. The difference between the fastest and the slowest board is approximately 3 fps. That changes as soon as you enable the sound system. Here, the difference is up to 8 fps.