Pixel Shaders and Physics

Marko Dolenc’s Fillrate Tester doesn’t support even Shader Model 3.0, but suits very well for analyzing graphics architecture performance with older shader code versions. The results obtained in this benchmark may be pretty valuable for those who still play old games. Besides, they give a more or less good idea of the GPU potential.

With simple shaders ATI Radeon HD 4850 yielded not only to Nvidia GeForce 9800 GTX but also to ATI Radeon HD 3870. However, since the speed of shader model 1.1 and 2.0 processing has been stumbling upon raster units performance for quite some time now (in this benchmark), the results are hardy surprising considering what we have just seen in fillrate tests. Pretty low performance of ATI Radeon HD 4850 in this shader model is very unlikely to affect the real gaming performance in any way.

As for the per-pixel lighting shader, the results here are quite logical considering the increased math1ematical potential of the new ATI RV770.

Shader Particles test from 3DMark06 suite is not a fully-fledged graphics test as it emulates a physical model of massive particle systems’ behavior. Collision calculations are performed using pixel shaders and the result is displayed on the screen using vertex shader texture samples. Nevertheless, this test can measure the math1ematical GPU performance just fine.

As you see, ATI Radeon HD 4850 demonstrates a 50% advantage over Nvidia GeForce 9800 GTX and almost 70% higher speed than ATI Radeon HD 3870 with half the math1ematical capacity of the ATI Radeon HD 4850.

Similar test from 3DMark Vantage suite for some reason doesn’t reveal any significant advantage of the new ATI architecture. However, ATI Radeon HD 4850 is at least as fast as Nvidia GeForce 9800 GTX. Looks like only every fifth ALU of our RV770 is really working in this test, but it turns out more than enough for results parity.

You all know Perlin Noise test from 3DMark06 suite as a “maximum” test for Shader Model 3.0 hardware. It generates a texture using 48 texture samples and 447 math1ematics instructions, which is maximum SM 3.0 hardware can handle.

Thanks to 800 streaming processors, ATI RV770 doesn’t disappoint us here: ATI Radeon HD 4850 is almost twice as fast as ATI Radeon HD 3870 and 70-75% faster than Nvidia GeForce 9800 GTX.

3DMark Vantage POM test shows stable advantage of our ATI Radeon HD 4850 over previous generation single-processor graphics cards. New ATI solution is almost twice as fast as its predecessor and 50% faster than Nvidia GeForce 9800 GTX at displaying the complex landscape with parallax occlusion mapping method.

Shader Math test is a slightly more complex version of Perlin Noise from 3DMark06. So, no wonder that ATI Radeon HD 4850 is also far ahead of the competitors here.

X-bit Mark test still illustrates remarkably well both: math1ematical GPU performance and their architectural success.

As you see, ATI Radeon HD 4850 is an indisputable winner in every subtest, where ATI solutions have never got even close to Nvidia GeForce 9800 GTX.

We can see a definite performance advantage over Nvidia GeForce 9800 GTX in all benchmarks. It is twice as fast in NPR shader with 10 texture samples, and more than twice as fast in shaders using complex calculations with loops and conditional branching. We didn’t have any doubts about the computational potential of the new ATI RV770 from the very beginning, but now we see for sure that the former curse of all ATI Radeon HD solutions – slow texture processors – has vanished without a trace. As a result, the new ATI Radeon HD generation deals brilliantly not only with pure math1ematics, but also defeats Nvidia solutions in their own element.