View Single Post
Old 08-01-09, 01:17 AM   #41
Posts: n/a
Default Re: EQ2 Shader 3.0 upgrade

Originally Posted by ChrisRay View Post
This was actually one of the hardest things for people to understand at the time. People assumed the Geforce 6 used the same shader setup as the FX cards and it didnt. People assumed FP32 would mean drastic slowdown on the NV40 and NV45. But the reality was there was too much going on in the pipeline for that ever to become a primary bottleneck. The 3Danalyze program was great for toying with this back when FP16/FP32 existed,

Actually if you look at these rightmark3d Benches. You'll notice the 7800/7900 series copes with 16FP-> 32FP even better than the Geforce 6 series. I cant say why the Blinn shader seems to do better. But my guess is its makes more use of MADD type instructions. As well other pipeline improvements. Obviously IMO the Geforce 6 and Geforce 7 still share heritage from the NV35/Nv3x. Something alot of people will not want to admit.
Yeah, the 6800 was quite a surprise. VLIW took a lot of the blame I remember, althoug that probably had more to do with how it handled registers, constant registers, and combiners. the 6800 was a NV20 repeat pretty much, even more so because it was such a saviour compared to the previous generation (whereas Geforce 2 was great). Btw, as an aside, I wonder if current programs benefit from the knowledge of shader optimizatino to lower precion targets gleaned during this amalgamam.

Last edited by pakotlar; 08-04-09 at 12:06 PM.
  Reply With Quote