How Unity, Compiz, GNOME Shell & KWin Affect Performance

Those that follow my Twitter feed know that over the weekend I began running some benchmarks of the various open-source and closed-source graphics drivers. But it was not like the usual Phoronix benchmarks simply comparing the driver performance. Instead it was to see how each driver performed under the various desktops / window managers now being used by modern Linux installations. In this article are the first results of this testing of Unity with Compiz, the classic GNOME desktop with Metacity, the classic GNOME desktop with Compiz, the GNOME Shell with Mutter, and the KDE desktop with KWin. These configurations were tested with both the open and closed-source NVIDIA and ATI/AMD Linux drivers.

While the original plans were grand, various Linux graphics driver bugs were hit along the way. For example, on Git master of Mesa and with the latest Linux kernel DRM from Linux 3.0/2.6.40 (it's likely a Mesa bug though), Compiz as found in the Natty repository is broken.

Running Compiz from either the GNOME classic desktop or Unity results in a completely broken experience for both the open-source AMD (R600g and R300g) and Nouveau drivers. I am not the only one hitting the problem including on Linux 2.6.39 and using the xorg-edgers PPA where Compiz/Unity is borked. That though was not the only problem. In other configurations with classic GNOME, there would also be text corruption occasionally.

On the next page are more Linux desktop issues encountered with the drivers followed by seven pages of performance results. [For those that don't like going through so many pages, you can subscribe to Phoronix Premium to view entire articles on a single page and without any ads. Phoronix Premium subscriptions also make for greater motivation to continue doing tests over the holidays.]