Jerykk wrote on Jan 3, 2011, 03:51:
DX10 allows for effects that would be cripplingly slow on DX9.
Such as? Remember how Crysis had a bunch of effects "exclusive" to DX10 until somebody edited the cfg files and made the effects work in DX9? And at a higher framerate? I have yet to see any DX10 "exclusive" effects that I haven't seen in DX9 at equal or better performance. Soft shadows? DX9. Soft particles? DX9. SSAO? DX9. HDR? DX9. FSAA? DX9. I'm very curious as to what effects DX10 can handle so much better than DX9.
Extrusion and tessellation are two examples. Those effects were done in DX9 games on the CPU, but DX10 enables geometry shaders for that purpose. The idea being that a game should be able to get them "for free". It's about performance. Which, as you pointed out, isn't always consistent due to the talent/experience/innovation of the coders and the code they write. Likewise various other improvements in the pipeline and in the API. You are right that DX10/DX11 doesn't magically enable effects that weren't possible before - in fact, any effect is possible in ANY version of Directx, or without it (like ray tracing on the CPU or a pure software renderer) - but it makes those effects efficient enough that they actually get implemented, or easy enough that they are implemented beyond triple A games. With one of the results being that more CPU cores are free to do other stuff, like AI, physics, pathfinding, sound or whatever.