KWin Can Cause A Performance Hit Too, But It's Different From Compiz

With World of Padman, we have the same story again:

- There's no measurable performance hit when running KWin with Intel graphics compared to the frame-rate drop experienced when running Compiz.
- With the open-source Radeon driver stack the OpenGL gaming performance is about the same between Compiz and KWin, which is slower than when running without a compositing window manager.
- The proprietary ATI Catalyst driver continues to perform the same regardless of the desktop window manager.
- The proprietary NVIDIA driver continues to be beaten when running a compositing window manager, but this time the KWin hit is more significant.

The Tremulous results are interesting on many different fronts with the open-source Radeon driver continuing to do better with this ioquake3 game when a compositing manager is enabled the frame-rate actually increases, the frame-rate also increases with a compositing manager when running the ATI Catalyst driver, and with the NVIDIA driver there is no measurable performance change with KWin/Compiz compared to Metacity.

Urban Terror is the same story with KWin on Intel doing better than Compiz on Intel, the open-source Radeon driver taking a hit regardless of the compositing window manager, the Catalyst driver performs the same, and the NVIDIA driver takes a slight hit when dealing with compositing.