CrossFireX Arrives: First Look at 3 and 4 GPUs in 2 Card Setups

The Elder Scrolls IV: Oblivion Performance

Version: 1.2.0416 Shivering Isles

Settings: Ultra High Quality settings defaults with Vsync disabled.

Our Oblivion test takes place in the south of the Shivering Isles, running through woods over rolling hills toward a lake. This is a straight-line run that lasts around 20 seconds and uses FRAPS to record framerate. This benchmark is very repeatable, but the first run is the most consistent between cards, so we only run the benchmark once and take that number.

Our tests show that moving beyond two GPUs in a DX9 game that already benefits well from multi-GPU has the potential to make use of three or four GPUs. As resolution goes up, the usefulness of more than two GPUs goes up. Clearly, there is potential for scaling with games that don't make extensive use of features that get in the way of multi-GPU performance. It should also go without saying that this is a technology that should be reserved for the ultra high-end setups. Hopefully illustrating that with resolution scaling will help bring the point home.

AMD tends to lead in this benchmark normally, and the 8800 Ultra barely leads the Radeon HD 3870, which is normally in competition with the GeForce 9600 GT. In this case, the 8800 Ultra SLI loses to the three GPU AMD setup (3870X2 + 3870), while four GPUs show an even more significant advantage at higher resolutions. 9600 GT SLI, which would normally compete with the 3870X2, doesn't really come through in Oblivion.

Enabling AA and AF reveals one of the major strengths of multi-GPU acceleration: antialiasing comes at less cost. In this case, even at lower resolutions, all four GPUs are able to contribute and performance stays high. While CrossFire and SLI both enable huge levels of AA, at high resolutions a little bit goes a long way.

While two 3870X2 cards do lead overall, 8800 Ultra SLI does best the three GPU combination of the 3870X2 and the 3870. Oblivion certainly shows that more than two GPUs can contribute to performance, and that AMD was right when they said DX9 games running under Vista would show the most potential for improvement with four GPU systems.