Vertex Shader Performance
3DMark 2001 SE may be working not quite correctly with RADEON X1800 and prerelease CATALYST driver version: the results demonstrated by the XT and XL models are exactly the same. Moreover, the performance doesn’t drop as the resolution increases.
High frequencies and 8 vertex processors make RADEON X1800 XT and XL the winners in 3DMark03 vertex shaders processing.
Simple Vertex Shader test deals with transformation and lightning of a few models with high polygon count. There are 6 million vertexes in this test with only one light source. The shaders used here belong to Shader Model 1.1. In this case RADEON X1800 XT is an indisputable winner. RADEON X1800 XL is also ahead of all other testing participants although the gap to the nearest follower is not as significant as between the top model and the others.
Complex Vertex Shader test is a much more complicated benchmark, because each blade of grass on the meadow shown in this test is processed individually. RADEON X1800 XL gives in here for some reason and lets the RADEON X850 XT Platinum Edition take the second prize. RADEON X1800 is still beyond any competition.
From the technical point of view, the geometrical Xbitmark test is very similar to Simple Vertex Shader test: we have to transform and light a few models with high polygon count, however this tie the number of light sources involved varies from 0 to 8. As the number of light sources increases, the performance of RADEON X1800 XT/XL doesn’t drop down as dramatically as that of the other testing participants. It means that the new ATI solutions boast highly efficient vertex processors and memory subsystem.