MikeTeo.net

If you find that your Gnome or KDE desktop feels laggy (i.e. the screen takes a while to redraw when you are switching between windows) even when there is no significant hard disk activity or CPU load, you might want to modify your xorg.conf to enable EXA.

Sign in as root user and edit /etc/X11/xorg.conf and add in

Option      "AccelMethod"   "exa"
Option      "MigrationHeuristic" "greedy"

under the Device section.

Your Device section will now look something like this:

Section "Device"
Identifier  "Videocard0"
Driver      "intel"
Option      "AccelMethod"   "exa"
Option      "MigrationHeuristic" "greedy"
EndSection

Save your file, log out of your Gnome/KDE desktop, and re-login again.

You can verify if EXA is loaded by opening /var/log/Xorg.0.log and check if the log file contains the following lines:

(II) EXA(0): Offscreen pixmap area of 6291456 bytes
(II) EXA(0): Driver registered support for the following operations:
(II) Solid
(II) Copy
(II) Composite (RENDER acceleration)