Geometry Performance

Simple Vertex Shader test from 3DMark06 is too simple, but at the same time it can beautifully show some peak geometry performance. The test barely suits to estimate the graphics architecture scalability, but ATI Radeon HD 4850 is the winner here.

As the resolution increases, ATI Radeon HD 3870 slows down. ATI Radeon HD 4850, in its turn, starts off slow and in 1280x1024 yields to the predecessor. However, by 1920x1200 it almost catches up with 3780. We don’t know up until now why RV670 behaves like that here.

This benchmark estimates the graphics architecture potential during vertex and geometry shaders processor and becomes the first benchmark where ATI Radeon HD 4850 falls far behind Nvidia GeForce 9800 GTX, although at the same time outperforms the previous generation ATI Radeon HD. It is pretty strange, even assuming that 4/5 of ATI Radeon HD 4850 computational capacity is idling because of poor drivers or even 3DMark vantage optimization. 160 active shader processors should be more than enough for the solution to successfully compete against Nvidia GeForce 9800 GTX.

All in all, the performance of ATI Radeon HD 4850 is pretty logical and speaks for itself. And first of all it indicates that new ATI architecture is almost free from any bottlenecks except a few doubtful results in several tests. Do these bottlenecks still exist? Only a test session is real gaming applications will answer this question, but it is going to be a topic for another article.

Although the computational capacity of the new RV770 has increased significantly, ATI Radeon HD 4850 behaves very strangely in Xbitmark geometry test: it suddenly yielded to ATI Radeon HD 3870. The defeat was most dramatic in scenes with 8 light sources. But even in this case, it ran faster than Nvidia GeForce 9800 GTX.