Vertex Shader Performance

The performance of the GammaChrome’s four vertex processors roughly matches that of the two vertex processors of the RADEON X600 PRO, but the performance of the S3 card falls almost to the level of the RADEON X300 as soon as 1024x768 resolution. This test is rather out-dated, though. Let’s see what we have in more up-to-date ones.

The GammaChrome S18 benefits by its four vertex processors in the analogous test from 3DMark03 ?this graphics card can’t catch up with the GeForce 6600 but leaves both cards from ATI Technologies behind.

The Simple Vertex Shader test from 3DMark05 isn’t as simple as its name implies. Here, transformation and lighting are performed over six models each of which consists of over a million vertexes.

The S3 GammaChrome S18 and the NVIDIA GeForce 6600 GT have four and three vertex processors, respectively. The performance of the two is similar in this test, though. This is a confirmation of our point that the efficiency of a vertex processor from S3 is lower than the efficiency of a vertex processor from NVIDIA, the clock rate being the same. Note also that the graph of the GeForce 6600 is almost a straight line, while the graph of the S3 GammaChrome S18 Pro shows a bigger dependence on the resolution.

The second vertex-shader-related test from the 3DMark05 suite is much more difficult than the first one: grass is being transformed and illuminated here. Each blade of grass is rendered independently, so the vertex processors of the graphics card experience a tremendous stress. The four vertex processors of the GammaChrome S18 show their best in this test: the card outperforms the RADEON X600 PRO and the GeForce 6600 in low resolutions. But in 1600x1200 the performance of the S3 card sinks to the level of the RADEON X600 PRO which has only two vertex processors.

The test, however, refused to work correctly with this graphics card and yielded extremely low results in all the modes. The imperfect drivers from S3 Graphics must be guilty again.