Performance: Synthetic Benchmarks

Fillrate

At first we will take a look at the Polygon Fillrate test from 3DMark 2001 SE test set. To evaluate the efficiency of technologies intended to optimize the use of memory bus bandwidth, we ran this test with enabled FSAA.

The results shown by NVIDIA GeForce FX 5600 Ultra and ATI RADEON 9500 Pro with enabled FSAA do not drop down as greatly as the results of other testing participants. This can be explained by the fact that only NVIDIA GeForce FX 5600 Ultra and ATI RADEON 9500 Pro support frame buffer compression.

With enabled multi-texturing the NVIDIA GeForce FX solutions and ATI RADEON 9500 Pro lay 8 textures per pass, unlike NVIDIA GeForce4 Ti4200-8x, MX440-8x and ATI RADEON 9000 Pro. As a result, they have to address the Z-buffer and frame buffer more rarely, so that enabled full-screen anti-aliasing hardly tells on their performance.

The fillrate tests from 3DMark 2001 can hardly allow us to draw final conclusions about the advantages of the NVIDIA GeForce FX internal architecture. We decided to make up for the missing information about the way NVIDIA GeForce FX organizes its architecture with the help of a small program which draws a surface with 0-4 textures laid upon it. To make the picture complete, I also added the results for NVIDIA GeForce FX 5800 Ultra (NV30):

NVIDIA GeForce FX 5800 Ultra and GeForce FX 5200 Ultra act very similarly, which proves the supposition about their identical internal architecture, with that only difference that GeForce FX 5200 Ultra feature only 2 pixel “pipelines” with two TMUs on each.

However, GeForce FX 5600 Ultra (NV31) stands out here: when there is only one texture laid, this chip shows better results than the theoretical maximum for configurations with two pixel pipelines. Of course, with only one texture processed NV31 uses the mode with 4 pixel “pipelines” and 1 TMU per pipeline. In case there are two or more textures to be processed NV31 resorts to a different internal organization scheme: 2 pixel “pipelines” with two TMUs per pipeline.

This flexibility should offer GeForce FX 5600 Ultra a significant advantage over NVIDIA GeForce FX 5200 Ultra even if they work at equal clock frequencies. In most today’s games there surfaces with a single texturing layer as well as surfaces with two and more textures. Note that the share of single-texture surfaces is not that small at all. In those cases when there is only one texture used on a certain surface, such as grass, tree leaves, various explosions, flames, smoke and clouds, NVIDIA GeForce FX 5600 Ultra will work twice as fast.