What are the differences between the various shader versions? There's 1.0, 1.1, 2.0 and, recently, 3.0. What are the differences between the shader versions? More features? Faster to render?

the higher the shader version the more instructions and the more possibilities and faster (because the gpu's are getting faster while higher shaderversions are developed and implemented)

its clear that a ps_1_1 shader with one instruction is faster than a 3.0 shader with 100 instructions.

the precision has changed from 1.4 to 2.0 which gives you softer shades for example

soon, i'll have a gf6800 maybe tomorrow and than there are no more limits

Generally lower shader versions will do the same task faster than a higher version, if only a little bit. this is because of certain hardware and driver optimizations. The general rule is, use the lowest shader version possible for the effect you want to achieve.

I'm using in all of my shaders shadermodel 3.0, because it's running faster then 2.0 on my GeForce 6600GT.

And if you're developing now a game, you can be sure that Shadermodel 3.0 is the default in the next year.

And don't forget, only NVidia GeForce 6600GT/6800GT/7800GT/7800GTX supports Shadermodel 3.0.

Model 3 will not be 'default' next year. You will be lucky if model 2.0 will be.

Shadermodel 3.0 will be the default on NVidia hardware, what is with ATI I cannot say. But games which are supported by NVidia will use Shadermodel 3.0 as their default. Look at Unreal Tournament 2007 which will be realeased next year: The unreal 3 engine is using shadermodel 3.0 as default.

Not as default, only as highest of all supported shader versions. But UT2007 will also run with 2.0 and lower cards - hardly anybody would even be able to play it if it only runs with 3.0.

You're right LordSebe, but I mean the default as the highest what is possible, and UT07 will not look as good as with Shadermodel 3.0.
And did you see what UT07 requires at hardware? I think I can't run it at the highest settings. I need a GeForce 7800GTX or better two!

It will probably look the same in any shader version. As far as i know, it's not doing anything so amazing.

The only difference between shader versions when you're compiling the same shader for different compile targets is accuracy- and this is mostly between ps1.x and ps2.0. Other than that, there won't be any visual difference. If the shaders don't compile on lower compile targets (due to too many instructions, unsupported instructions etc.), then you will have a possible visual degration because the code had to be simplified to fit in the constraints of the compile target.

-Rhuarc