Pipline debate (cont’d)

In the whitepaper, NVIDIA brings up a very valid point in that the first game test uses a significant amount of single texturing but with GeForce FX 5800 Ultra’s 500MHz core clock and 8-pixel pipelines NVIDIA theoretically has an advantage over RADEON 9700 PRO in these situations (4,000 Mpixels/sec in GeForce FX versus 2,600 in RADEON 9700) so why should they complain? Lets use 3DMark to see just what kind of fill rate GeForce FX actually delivers:

Fill rate Performance

As you can see in our test results, GeForce FX delivers similar results to what you’d expect from a 4-pixel pipeline architecture (like the GeForce4) in single-textured situations. NVIDIA’s gripe with game test 1 begins to make more sense. NVIDIA has responded by saying that the GeForce FX runs at 8 pixels per clock in:

a) z-rendering
b) stencil operations
c) texture operations
d) shader operations
For advanced applications (such as Doom3) *most* of the time is spent in these modes because of the advanced shadowing techniques that use shadow buffers, stencil testing and next-generation shaders that are longer and therefore make the apps "shading-bound" rather than "color fill-rate" bound.
Only color+Z rendering is done at 4 pixels per clock, all other modes (z, stencil, texture, shading) run at 8 pixels per clock.

So essentially, GeForce FX has been designed for more forward-looking titles at the expense of older single-textured applications. As you can see its 4x2 architecture gives it a multi-textured fill rate advantage over RADEON 9700 PRO, 4,000Mtexels/sec versus RADEON 9700 PRO’s 2,600Mtexels/sec. Is this as big a deal as some are making it out to be? Not according to Serious Sam programmer Dean Sekulic:

Just wanted to write a word or two regarding the issue raised couple of days ago. Seems like the whole Internet community wants to crucify nVidia about the controversy of how many rendering pipelines GeForceFX realy has. Is it 8 pipelines with 1 texture unit, or 4 with 2, or ... uh... I don't know anymore. And it really DOESN'T matter that much!

The only thing that matters is how fast and how good it can render pixels. And both GeForceFX and Radeon9700 are great products, the kind of hardware that developers long for. So, personally, I don't care much what's "under the hood".

Don't get me wrong, I am into 3D-graphic hardware, but this pipeline thing really went out of proportion. Number of pipelines is a good hardware information, and that's all there's to it. It really doesn't need to reflect the speed of the hardware directly. Come to think of it... currently, there are no games that utilize even 1/3rd of nifty features these two boards have.

Oh, before I forget... I'm not "nVidiot" (and I'm not "fanATIc", either). I'm just a game developer who wants good and fast technology for the future. And both ATI and nVidia have it now!

When push comes to shove, Dean hits the nail on the head. Both the GeForce FX and RADEON 9700 are more than capable of handling today’s latest games and software applications. Until the first wave of DirectX 9 games is released we won’t truly know whose design is best. What we do know is that ATI’s RADEON 9700 has been available for months now, so NVIDIA has a lot of catching up to do if they wish to recapture the high-end segment.