Virtual Pipelines.

[VIAN]

http://www.dvhardware.net/article2502.html

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.

 

[otispunkmeyer]

yeah i was wondering bout this too, when i saw the rumoured specs to G70, 32 pipelines 24 of which are real

cheers

 

[otispunkmeyer]

hmm just read that lol, got bit scared there when they put NV40 and 8 pipelins in the same sentence..but then i realised this was pre release info

 

[VirtualLarry]

Yeah, that article was written before the NV40's actual release, so it's half-speculation from The Inq. Most people at the time couldn't believe that the GPU would make the quantum-leap forward to having 16 "real" pipelines, so they were speculating (based on the dual/split nature of them), that they were 8 actual, but could function as 16, combined with a misunderstanding of a new feature of SM3.0 that was present on the cards, the ability for the VS pipelines to do reads of textures from the pixel units. (I wasn't aware that it could write to pixels, I don't think that part is accurate.) Thus the 3DMark2001 results that show 16 pixels/clock fill-rate is in fact accurate, but indicative of the GPU's 16 "real" pipelines. But for Doom3, it can run in "32x0 mode", giving it double the effective pixel "fill rate" for calculating shadows and things. (I'm sure I just made hash of the actual specifics, but that's the general idea here.)

That article really doesn't have anything to do with the upcoming NV parts currently being speculated about. Still a fun read though.