Ending some results at a lower resolution where the graphics hardware and driver are less busy still results in OpenGL regressions from the Intel Core i5 system with the newest Quantal packages.
It's unfortunate -- especially with the dismissal of the Compiz-less Unity 2D desktop from Ubuntu 12.10 -- but the Unity/Compiz performance continues to be a very visible blemish for the Ubuntu desktop. It's just not in OpenGL benchmarks where the performance degradation is visible and of no relevance to the real world, but it's very easy to find mentions within forums, Twitter, and elsewhere where some games (especially on the open-source drivers) aren't exactly playable with Unity but when switching to Xfce or other alternative desktops it becomes "brilliant", as said by one Phoronix reader. The Ubuntu 12.10 Beta is imminent and even with the latest Unity/Compiz updates the performance is still troubling, as the cross-desktop results in an upcoming Phoronix clearly illustrate.
The removal of Unity 2D is also equally problematic -- or even bigger -- for those Ubuntu ARM users. When there's no 3D hardware acceleration support available for Unity/Compiz, it's falling back to using the Gallium3D LLVMpipe driver. This isn't too much of a problem for Ubuntu x86 users, since there most hardware is backed by working open and closed-source graphics drivers but even without the hardware support, LLVMpipe is enough for powering a simple desktop assuming you're on a modern multi-core CPU and you'll find the best results if using x86_64 binaries and the CPU supports modern instruction sets like SSE4. The real problem is with ARM where there isn't any "out of the box" 3D support for ARM hardware for the SoC vendors not (yet) backing fully open-source driver stacks. Therefore, the clean Ubuntu ARM install experience will be left using Unity over LLVMpipe where on ARM it's far from being optimized. ARM hardware in the first place isn't as fast as a modern x86 desktop CPU but the LLVMpipe driver doesn't yet have ARM NEON support or other optimizations for providing decent software-accelerated 3D support, so the experience is basically a mess and a huge regression in the user experience compared to offering the Unity 2D option. Loading the processor up with OpenGL work also isn't too good for power usage.
Stay tuned to Phoronix for more Ubuntu desktop benchmarks as the 12.10 Quantal release approaches. If you appreciate this continued work that is done single-handedly, please subscribe to the single-page-articles without-ads option or follow the requests made at the end of this post.