az nVidia vezetö fejlesztöjét - David Kirk - olvashatjátok el: Kikapok érdekesebb részeket:
FiringSquad: Could you give us more details on your recent decision to emphasize HLSL over Cg?
Go back, say around two to three years when we started working on the FX architecture, we began to realize that complex programmable pipelines were going to require a high level language, and at that time there was no HLSL and we were working with other people in the industry including Microsoft to try and promote a programming language but we were not able to get any interest. So we started our own effort to develop Cg because we knew it would be required, whether or not anyone else thought it was important or not.
FiringSquad: Can you give us maybe a little background on why you guys decided on FP32 versus FP24?
Kirk: I think that’s a very interesting question. If you go back to how DX9 was developed it wasn’t clear as we were doing our development and Microsoft was doing their development and ATI was doing their development what the target precision was going to be for DirectX. If you look at processors FP24 doesn’t exist anywhere else in the world except on ATI processors and I think it’s a temporary thing. Bytes happens in twos and fours and eights -- they happen in powers of two. They don’t happen in threes and it’s just kind of a funny place to be.
FP24 is too much precision for pure color calculations and its not enough precision for geometry, normal vectors or directions or any kind of real arithmetic work like reflections or shadows or anything like that.
FiringSquad: One of the things that ATI has kind of said, or least they were suggesting at Shader Day is the fact that they can do more floating-point operations than you guys can. How would you respond to those types of statements?
Kirk: Well I guess the first response would be of course they would say that. But I don’t really see why you or they would think that they understand our pipeline, because in fact they don’t. The major issues that cause differing performance between our pipeline and theirs is we’re sensitive to different things in the architecture than they are so different aspects of programs that may be fast for us will be slow for them and vice versa.
FiringSquad: Could you give us specific examples of where maybe you feel you guys, you mentioned you guys can do some things better than they can, can you give us some specific examples of that?
Kirk: Well one example is if you’re doing geometric calculations with reflections or transparencies and you need to do trigonometric functions. Our sine and cosine takes two cycles theirs takes eight cycles, or seven cycles I guess.
Half-Life 2 performance/Conclusion
FiringSquad: So would you say that it’s a software type of issue that can be corrected?
Kirk: Yeah I don’t think there’s any issue with the hardware.
Bye mindenkinek, majd jövök. Bocsánat aki nem tud angolul, sajnos nincsen idom most leforditani. Ilyen cikkeknek örülnénk a pH!-n sztem :)
Liƒє is too short. - http://www.lowcostdomain.eu