Pixel filling power
We'll start off with our traditional look at fill rate, one of the more important factors in determining overall performance of a graphics card. Of course, raw theoretical fill rate can't be divorced from its most likely real-world constraint, memory bandwidth, so we have numbers on that, too. The table below shows specs for some top-end graphics cards in the past two years or so, sorted in order of memory bandwidth.

Core clock (MHz) Pixel pipelines Peak fill rate (Mpixels/s) Texture units per pixel pipeline Peak fill rate (Mtexels/s) Memory clock (MHz) Memory bus width (bits) Peak memory bandwidth (GB/s)
GeForce FX 5800 Ultra 500 4 2000 2 4000 1000 128 16.0
Parhelia-512 220 4 880 4 3520 550 256 17.6
Radeon 9700 Pro 325 8 2600 1 2600 620 256 19.8
Radeon 9800 Pro 380 8 3040 1 3040 680 256 21.8
Radeon 9800 Pro 256MB 380 8 3040 1 3040 700 256 22.4
GeForce 6800 325 12 3900 1 3900 700 256 22.4
Radeon 9800 XT 412 8 3296 1 3296 730 256 23.4
GeForce FX 5900 Ultra 450 4 1800 2 3600 850 256 27.2
Radeon X800 Pro 475 12 5700 1 5700 900 256 28.8
GeForce FX 5950 Ultra 475 4 1900 2 3800 950 256 30.4
GeForce 6800 GT 350 16 5600 1 5600 1000 256 32.0
GeForce 6800 Ultra 400 16 6400 1 6400 1100 256 35.2
GeForce 6800 Ultra Extreme 450 16 7200 1 7200 1100 256 35.2
Radeon X800 XT Platinum Edition 520 16 8320 1 8320 1120 256 35.8

If fill rate were money, the Radeon X800 XT Platinum Edition would be Bill Gates. If it were water, the X800 XT would be Niagara Falls. If it were transistors, the X800 XT would be a GeForce 6800 Ultra.

Err, strike that last one.

However you put it, the Radeon X800 XT Platinum Edition has helluva lotta grunt. The GeForce 6800 Ultra Extreme isn't far behind it, though, assuming they'll both be largely limited by available memory bandwidth.

In the $399 category, the 12-pipe Radeon X800 Pro just leads the 16-pipe GeForce 6800 GT thanks to the Radeon's much higher clock speeds. The memory bandwidth advantage, however, is clearly with the GeForce.

How do these numbers play out in synthetic fill rate tests?

In 3DMark03's single-textured fill rate test, the GeForce 6800 Ultra cards actually manage to outdo the Platinum Edition, probably because of more efficient management of memory bandwidth during the execution of this test. When it comes time to apply more than one texture per pixel, the X800 XT PE edges ahead slightly.

Let's stop once more to remind ourselves what a huge performance leap we're seeing from one generation to the next. The Radeon X800 XT PE delivers over twice the fill rate of the Radeon 9800 XT. Yikes.

Rightmark allows us to scale up the number of textures, unleashing the X800 XT PE's inner demons. When applying one texture, the NVIDIA cards have a big relative advantage. Moving two textures, the picture changes, and the ATI cards look relatively stronger. Once we get into three or more textures, though, the Radeons dominate. So it's a bit of a wash, depending on the scenario. Keep these differences in texturing and fill rate performance in mind as you read the rest of the results, because they will be enlightening.