SLI Benchmark Tests - 6800XT cards

At 3D Flight Sim we installed 2 XFX™ 6800XT cards in our model 3D-1000 high performance PC. Two benchmark tests were performed: 3DMark 2005 and FS9. Each test was performed at two screen resolutions: 1024 x 768 and 2048 x 768. The 2048x768 screen was created using the Matrox DualHead2Go. This allowed a single eDimensional video adapter to feed 3D stereo imaging to 2 CRT monitors.

The 3DMark tests were run at two settings for each screen resolution: 1) with no anti-aliasing and bilinear filtering, 2) 4 x antialiasing and 4s anisotropic filtering. The results are shown in the graph below:

We were pleased to find that the scores with SLI engaged greatly outpaced the non-SLI configuration. However, FS9 did not show the same performance gain.

FS9 was tested over 2 minute intervals with the simulation set at it's most demanding levels. For instance, it was found that the virtual cockpit display causes a greater load on the graphics processing than the flat 2D cockpit display. All tests were made with the VC view, and with other settings cranked up for the greatest graphics loading.

It is apparent that FS9's graphics, as for many current video games, does not take full advantage of SLI technology. A substantial performance gain was still found, however, at the higher screen resolution. We expect that future drivers and the new FSX flight simulator will produce sizable performance gains with SLI.

It is notable that our tests show how engaging 3D stereo puts a heavy load on the graphics card. When using 3D glasses little performance gain was found with SLI engaged. In either case the frame rates were still ample, however, for producing excellent stereo graphics.