Using an unaccelerated driver (vesa, radeonhd) with current git xserver is noticably slower than with Xserver 1.4 (you can actually watch how a window is drawn from top to bottom even on machines with very decent CPUs). Performance with accelerated drivers (intel, ati) is roughly the same as with 1.4.
This was libpciaccess using the sysfs maps for PCI BARs, and thus getting screwed by not getting write-combining. Thanks linux! You rock.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.