i guess you experience lagging when you try run a 3d application or watch a video. This happens because you haven't 3d accleration.
So if you use the original kernel you simply can install the fglrx driver from package. Code: aptitude install fglrx-driver fglrx-control fglrx-kernel-src
aptitude install module-assisstant
m-a prepare #m-a is the short name of module-assistant
m-a update
m-a a-i fglrx
depmod -a
modprobe fglrx
use aticonfig to configure your xserver
aticonfig --help
after configuration of X
/etc/init.d/{kdm|gdm|xdm} restart #need only one which are you using
then you can run fgl_glxgears to checking the driver
2.
top is show the actually running processes and its cpu usage |