Fedora Project has been on the forefont of development and adoption of kernel mode setting to enhance the desktop linux experience by making fairly invasive infrastructure improvements that affect the interaction between Xorg and the Linux kernel. In the past, one of the common way to test Xorg performance has been to use glxgears. While that hasn’t been a particular good way to do it ever, the switch to kernel mode setting for Intel drivers ahead of the Fedora 11 Beta release to be available shortly has exposed the fallacy of this. In short, don’t use glxgears. There are better methods to assess performance.