Futuremark 3DMark06 build 120
The results of GeForce 7900 GT and Radeon X1800 XT are only 100 points apart. Taking into account the requirements 3DMark06 sets to the graphics subsystem, as well as the price and power consumption of Radeon X1800 XT, the obtained results are quite an achievement for the Nvidia GPU. When we talk about multi-GPU systems, the performance difference between GeForce 7900 GT SLI and Radeon X1800 XT CrossFire is slightly bigger and equals 186 points. Although, this is a total score diagram and it represents more or less generalized numbers, which do not illustrate the performance of our solutions in SM2.0 and SM3.0/HDR tests. Now let’s take a look at each test separately for more information.
GeForce 7900 GT is only 31 points behind Radeon X1800 XT. Its 24 texturing units make up for lower clock speed. The GeForce 7900 GT SLI configuration also proves quite successful here, as it is only 60 points behind Radeon X1800 XT CrossFire. Our hero owes this excellent result to the fact that Radeon X1800 XT cannot really benefit from its great ability to process complex v.3.0 shaders.
In SM3.0/HDR tests, the single GeForce 7900 GT loses to Radeon X1800 XT a little bit more: 62 points. It could be the relatively low fillrate of Radeon X1800 XT as well as the absence of Fetch4 function that determined these results. The latter function serves to speed up dynamic shadows processing through Cascade Shadow Maps used in 3DMark06.
Unlike the systems with single graphics cards, Radeon X1800 XT CrossFire manages to leave GeForce 7900 GT SLI farther behind: the gap makes over 200 points.
Since GeForce 7900 GT GPU cannot use full-screen anti-aliasing and HDR at the same time, we will only show the SM2.0 results that we have obtained in FSAA 4x + AF 16x mode. In more resource-hungry AA modes, the performance is so low that we cannot take the measurements correctly. Besides, we have also omitted the 1600x1200 resolution, because 3DMark requires 512MB of onboard graphics memory for the system to run with anti-aliasing enabled.
When we enabled FSAA and anisotropic filtering, GeForce 7900 GT could compete with Radeon X1800 XT on equal terms only in 1024x768. In 1280x1024 the memory subsystem performance turned into a bottleneck for the newcomer. And the overall good results in the first SM2.0 test can certainly be explained by the 24 TMUs it has.
The results of Game 2 test prove everything I have just said. This test is not so fillrate-hungry, so Radeon X1800 XT benefits a lot from its higher clock speed and its ability to process pixel shaders fast enough. It manages to get about 35% ahead of GeForce 7900 GT in 1280x1024, while in the previous test the performance difference was only 10%.
In this case the individual benchmark analysis doesn’t prove the total scores: GeForce 7900 GT yields to Radeon X1800 XT in both SM2.0 tests. However, we should remember that the results of individual tests have been obtained with enabled full-screen anti-aliasing, which uses a lot of the memory subsystem resources.