Nv30's triangle setup engine more limited than R300's?

[Luminescent]

Initially it was announced that the NV30 was capable of transforming 350 million verts/sec. Some sites claimed tris/sec and some verts. Now the specs state 200 million tris/sec setup. Can it be that the NV30 indeed has 12 units to perform 3 sets of dp4's (3 virtual vertex shaders) for a 350 million vert/sec rate but is triangle setup limited like the parhelia?

 

[Himself]

I think all the BS spec numbers are just that, BS. Just wait for the reviews and see how well it does in benchmarks.

 

[Arun]

I've already explained this about a billion times at nV News...

Basically, the GFFX doesn't have the bandwidth to do 350M Vertices/s
The GFFX is all about quality, not quantity.

The GFFX Triangle Setup can only do 200M Tris/s - Triangles *cannot* be of higher quality and it's always pretty much the same speed.

So it's useless to have 350M Tris/s - you're never going to have that due to bandwidth limitations. The 350M Vertices/s is only useful when you've got very complex vertices, and then you aren't going to have more than 200M Vertices/s because each vertex will take more time to proccess.

If the GFFX had a 256-bit memory bus, it would indeed be triangle setup limited. But right now, it's memory limited


Uttar

 

[Luminescent]

What I would like to know is why Nvidia did not remain consistent with 1 set of numbers. Either list peak theoritcal vertex shader throughput or a closer-to-actual triangle rate which takes setup into consideration; both creates confusion unless specified.

 

[Xmas]

The important number is VS ops/sec.
Triangle setup won't limit in anything but the most theoretical benchmark situation.

 

[gkar1]

I've already explained this about a billion times at nV News...

Basically, the GFFX doesn't have the bandwidth to do 350M Vertices/s
The GFFX is all about quality, not quantity.

I know its a bit OT, but I couldn't help but laugh.
I expect those kinds of comments to come from PR people or salesmen

 

[K.I.L.E.R]

LOL, Uther the Lightbringer is really David Kirk in disguise.

 

[Arun]

Yeah, I know, it sounds a lot like PR
But hey, it's really the only way to explain that...
Or do you know a better way?


Uttar