More NVIDIA NV40 news

It will have 8 physical pipelines, but these appear to act like 16 in certain games and in 3DMark 2001. It will score 6500Mtexels per second in 3DMark01, where ATi's Radeon 9800 PRO only scores half of that.

Nvidia was telling people how 3DMark01 is a very nice benchmark since they can render 16 pixels per pass in it, using only eight pipelines. What Nvidia is using is the ability of the Vertex Shader model 3.0 (known as PS 3.0 or VS 3.0) where the Shader can actually render pixels as a virtual pipeline. But it can only render them without filtering information other than Point Sampling, a basic filter technique.

But, in modern games you always apply Bilinear, Trilinear or Anisotropic filtering to pixels that you render, otherwise they will have some visual malformations. This is why, in normal games, eight pipelines will be able to render eight pixels in single texturing pass and possibly even 16 if you render both pixels in same pass using an 8x2 architecture.

What we understand Nvidia is doing is applying eight textures to eight pixels using the Pixel Shader, while the other eight textures get applied to another eight pixels by Vertex Shader. If they decide to use this in modern games this would roughly mean that they can render every second texture properly, which would mean that you would be able to notice the difference. However, this can be tweaked in the driver if they decide to go that way, but image quality would have to be sacrificed for that.

To get into more details, the Vertex Shader model 3.0 feature has the ability to fetch textures but you could use your VS 3.0 only where you don’t have any geometry - when you have to process just pixels. This cannot be used in modern games as you process just point sample textures. In 3DM2001SE you get such high numbers because you deliver 16 pixels per clock.

We asked Nvidia to comment but since they haven’t announced NV40 they sdaid they can't comment on "unannounced products". But we expect they will be able to tell us more then they launch on 14th in the old continent.

However, we expect NV40 to deliver 16x1-like performance in Doom 3 (or should we say 16x0, which is how people call Nvidia's approach) where they render all the information except Z or colour features. This will be used by Doom III and games based on this engine.