Editing xorg.conf for a particular resolution

BlackSheep024 · 08-20-2009, 08:52 AM

OS-Ubuntu 8.04
Drivers-Catalyst 9.3
Video Card-Radeon 9800XT
Situation:

I've installed the ati drivers, and have restarted my computer to find my resolution set to 1280 x 720. I've set it to 1024 x 768 in amdcccle both as the regular user and as the super user, and still no luck. Every time Ubuntu starts, it starts in 1280 x 720. Any help would be greatly appreciated.

PS-My monitor supports 1024x768 @ 85hz, but aticonfig forces me to use a refresh rate of 75. Any help here would also be appreciated.

my xorg.conf in it's current state:
-----------------------------------
Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "aticonfig-Screen[0]-0" 0 0
EndSection

Section "Files"
EndSection

Section "Module"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Monitor"
Identifier "aticonfig-Monitor[0]-0"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
EndSection

Section "Device"
Identifier "Configured Video Device"
EndSection

Section "Device"
Identifier "aticonfig-Device[0]-0"
Driver "fglrx"
BusID "PCI:2:0:0"
EndSection

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

Section "Screen"
Identifier "aticonfig-Screen[0]-0"
Device "aticonfig-Device[0]-0"
Monitor "aticonfig-Monitor[0]-0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection

tommcd · 08-21-2009, 03:27 AM

See this page about how to specify refresh rates and screen resolution in xorg.conf:
http://ubuntuforums.org/showthread.php?t=83973
and:
http://www.linuxquestions.org/questi...g.conf-317105/
Just add the appropriate HorizSync and VertRefresh lines in the "Monitor" section' and the modes line in Section "Screen", SubSection "Display".
You can generate mode lines using gtf or cvt commands. For example, for 1024x768 at 60Hz, the commands would be:

Code:

gtf 1024 768 60
  # 1024x768 @ 60.00 Hz (GTF) hsync: 47.70 kHz; pclk: 64.11 MHz
  Modeline "1024x768_60.00"  64.11  1024 1080 1184 1344  768 769 772 795  -HSync +Vsync

or:

Code:

bash-3.1$ cvt 1024 768 60
# 1024x768 59.92 Hz (CVT 0.79M3) hsync: 47.82 kHz; pclk: 63.50 MHz
Modeline "1024x768_60.00"   63.50  1024 1072 1176 1328  768 771 775 798 -hsync +vsync

Use one or the other, not both. You may get different values for your monitor.
Xorg.conf is mostly empty these days. The X server should still honor anything you put in there though.
I don't know anything about how to properly configure the ATI drivers though. I use nvidia.