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This may help some people with older ATI graphics.

Posted: Sat Mar 21, 2009 11:59 am
by exploder
I saw this today on the Ubuntu forums and thought it might help people using older ATI graphics cards running KDE 4.2. This is taken directly from the post.


radeon driver improvements
KDE 4.x replaces the infamous kicker panel with plasma. Plasma makes heavy use of argb, which hammered my ati card. It's an old card and the proprietary drivers don't support it. The new radeonhd drivers don't support it.

I'm using a FireGL 9000 (chipset r250).

Using the autogenerated settings, my CPU was running at anywhere from 30 - 80 percent load, just to support the desktop. Needless to say, actually using the computer was a real challenge.

After doing some looking around on the net and experimenting with some different values, I have come up with an xorg.conf file that lets me use the radeon driver for KDE 4.2 without stressing the hell out of my CPU.

Code:

Section "Device"
Identifier "Configured Video Device"
Driver "radeon"
Option "AccelMethod" "EXA"
Option "MigrationHeuristic" "greedy"
Option "AccelDFS" "true"
Option "EnablePageFlip" "true"
Option "EnableDepthMoves" "true"
Option "AGPMode" "8"
Option "ColorTiling" "on"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection

Section "Module"
Load "glx"
Load "dri"
Load "drm"
EndSection

Section "DRI"
Group "video"
Mode 0666
EndSection

My CPU is now running 1 - 5 percent, to support the KDE desktop. Needless to say, I am pleased. I do not claim that this is perfect and I would certainly appreciate any feedback / advice on what I've come up with. When jaunty hits gold, it would be nice if we could have some documentation to help people use older ati cards with modern desktops.

This guy had success, hope his experience will help others.

Re: This may help some people with older ATI graphics.

Posted: Sun Mar 22, 2009 10:55 am
by Husse
Would this be useful for non KDE4?
Seems so apart from Option "MigrationHeuristic" "greedy" which I know nothing about

Re: This may help some people with older ATI graphics.

Posted: Mon Mar 12, 2012 12:52 am
by Geoff55
That's a really useful tip.

I tried KDE about 6 months ago and gave up, because it was so heavy on the CPU. I didn't even think it would be the ATI card. It's a AGP x8 9600 radeon with 128mb. The PC is P4 with 2 GB which can be upgraded to 4 GB.