what is it? 4 dawn fairys done by nv35?

[rwolf]

Unfortunately you have two choices. Crappy looking or slow (fp16 or fp32).

[DSC]

IMHO, it would be better if Nvidia make an option so you can select all 4 of them to do different things at the same time. If the NV35 can render all of them doing different things at the same time @ 60FPS, then I would be impressed.

[Uttar]

Originally posted by rwolf
Unfortunately you have two choices. Crappy looking or slow (fp16 or fp32).

*sigh* When will you people understand that FP16 is sufficent for a *lot* of things.
In many cases, FP16 gives the exact same 8-bit output as FP32!

But not in all cases. And when it doesn't, it can give bad artifacts.

FP24 is good in most things FP16 is bad. But in some cases, you still need true FP32 to get a correct results.

The cases where FP24 is insufficent are very, very rare however. FP16 being insufficent is much more frequent.


Also note that the NV3x architecture supports INT12 ( 12-bit Integer )
INT12 is sufficent in quite a few cases, but it gives horrible artifacts in some.
INT12 is *not* supported in DX, only in OpenGL. INT12 is, however, what's used for PS1.1.->1.3. in DX

The NV3x can get a *huge* performance boost when using both Integer and FP in a same program, because it can do *both at the same time*
Carmack is nearly certainly using this in his NV30 profile, because the performance boost can be amazing.

I'd speculate Carmack is using FP32, FP16 *and* INT12 in his NV30 profile ( mostly FP16, with some INT12 and a little FP32 ) The result should be slightly lower quality than the R300's FP24, but it should not be noticable to the bare eye if Carmack wasn't too aggressive.


Uttar

[GlowStick]

Originally posted by DSC
IMHO, it would be better if Nvidia make an option so you can select all 4 of them to do different things at the same time. If the NV35 can render all of them doing different things at the same time @ 60FPS, then I would be impressed.

DSC you are actually right on the button.

That isthe whole key behind the gffx. You can have each shader run in a diffrent persicison etc.

basicly if you made a game that can predict what parts will need high percision (decided by the artist) they can have that dose in high perscison where other areas dont.

eg, in the dawn demo im sure her wings are done in fp32, where the background could be done in fp16 (since i dont know how 3d games work im kinda guessing that the terms fp16/32 apply there ; )

though programmers may never use it.

[rwolf]

I don't think that is how it works. JC talked about different "code" paths for 16-bit/32-bit.