We ran the gears, text, and image scaling tests again with QGears2 but now using the OpenGL back-end. When running gears with the OpenGL interface, the performance was roughly the same between the two Ubuntu releases except that the 9.04 release was slightly slower (84.37 versus 81.69 frames per second).
A more noticeable drop in the OpenGL performance was evident with the text operation in QGears2. Ubuntu's graphics stack in 8.10 had led to an average frame-rate of 13.62 while with Ubuntu 9.04 it was at 11.87 FPS.
In our final test, which looked at the image scaling performance using OpenGL, the results were nearly identical.
The EXA / X Render performance has certainly improved in the open-source ATI stack between the Ubuntu 8.10 packages and now with Ubuntu 9.04. The GtkPerf numbers were dramatically better and these results were carried through as well with the Qt4-based QGears2 results. The OpenGL performance on the other hand has not improved much. Most native Linux games are still unplayable with the Mobility Radeon X1400 when using the open-source ATI stack and with the proprietary Catalyst driver its R300 through R500 support is being dropped. The performance will improve once the ATI driver has proper kernel-based memory management and it has moved over to the Gallium3D driver architecture. It is possible these changes could be done in time for Ubuntu 9.10, but chances are it will not really come into fruition until Ubuntu 10.4 LTS.