Shader Model 3.0 - What's it all about?

[rbV5]

Hanners of elitebastards has whipped up an interesting short but concise informational piece on DX9 shader model 3.0 and its basic differences from 2.0.

Link

 

[Acanthus]

All the features that should have been in 2.0 imho

 

[rbV5]

The use of dynamic flow control is mainly as a vehicle to gain performance when executing shaders - In theory, this should prevent unnecessary execution of shaders, as well as cutting down the lengths of shaders that a GPU has to run by skipping instructions that aren't required

Well that puts this comment from the ATI "leak" into perspective I guess. I take it that developers using flow control in PS 3.0 will show enough of a performance hit on ATI's part to clearly show a difference from NV's part. Probably also answers the question of 420's PS 3.0 support.

Steer people away from flow control in ps3.0 because we expect it to hurt badly. [Also it's the main extra feature on NV40 vs R420 so let's discourage people from using it until R5xx shows up with decent performance...]