I have strange problem with my ATI x1950 pro AGP card and Linux with Catalyst 8.1 Linux drivers.
After successfully install of this driver and reboot my PC I always get a short white horizontal lines over the gdm screen. When I want to login and when system start to entering into GNOME, the system hung. Cursor stopped, trying to go into console (CTRL+ALT+F1) is unsuccessful and only what I can is hard reset PC.
This happened always (with cooled and warmed PC).
Can be a hardware failure of graphic card, or something else?!
If you don't see corruption in the BIOS POST or the console while booting, chances are your card is OK (though the 3D part could be failing). Do you have 3D desktop compositing effects (compiz/Beryl) running in your session?
Yes, I'm using compiz, but gdm (where white stripes appeared) is not using 3D effects yet.
I found this on ATI's page:
For AGP ( Accelerated Graphics Port) cards ensure:
* Ensure that Fastwrite is disabled in BIOS, and in the SMARTGART section of ATI’s Catalyst Control Center
* Try adjusting the AGP speed from (8X to 4X) (4X to 2X) or vise versa.
* Increase the AGP Aperture in the BIOS. We recommend a 128MB minimum.
* Disable any Shadowing settings in the BIOS.
* Disable any Cache Video BIOS settings in the BIOS.
So, I must check this settings in my BIOS, too.
On Unofficial ATI Wiki I found something about UMA and SIDEPORT modes, but where I can set this options??