Setting dual monitor with different resolutions using ati open source driver

Question

I have two Monitors and am using Arch Linux, setup like this:

• 1280x1024(primary)
• 1680x1050.(secondary)
• ATI RADEON X1300
• Open source ATI driver

On the boot screen my primary monitor(17") have correct resolution, my second CLONES the first and has same resolution(1280x1024).

I have to run xrandr TWICE after starting X to get correct resolution.

xrandr --output DVI-0 --mode 1280x1024 --output DVI-1 --mode 1680x1050 --left-of DVI-0

I tried to make this permanent, by adding the xrandr command to .xinitrc, but it didn't work. Now, if I wan't to get the correct resolution on both monitors, after starting X, I run xrandr TWICE.

I didn't define anything in xorg.conf (nor do I know how :) ) What can I do to fix this?

Answer 1

I ran into this problem a couple times as well.

For some reason, my screens have a nasty habit of changing their "name" sometimes, rendering whatever piece of code I set out with xrandr useless.

First double check that the monitors are correctly identified:

xmax@max-desktop:~> xrandr
Screen 0: minimum 320 x 200, current 3360 x 1050, maximum 3360 x 1050
DFP1 disconnected (normal left inverted right x axis y axis)
DFP2 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
   1680x1050      59.9*+
   1400x1050      59.9  
   1600x900       59.9  
   1360x1024      59.9  
   1280x1024      75.0     60.0  
   1440x900       59.9  
   1280x960       60.0  
   1280x800       60.0  
   1152x864       59.9     75.0  
   1280x768       60.0  
   1280x720       60.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3     56.2  
   640x480        75.0     59.9  
CRT1 disconnected (normal left inverted right x axis y axis)
CRT2 connected 1680x1050+1680+0 (normal left inverted right x axis y axis) 474mm x 296mm
   1680x1050      59.9*+
   1400x1050      59.9  
   1600x900       59.9  
   1360x1024      59.9  
   1280x1024      75.0     60.0  
   1440x900       75.0     59.9  
   1280x960       60.0  
   1280x800       60.0  
   1152x864       59.9     75.0  
   1280x768       60.0  
   1280x720       60.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3     56.2  
   640x480        75.0     59.9  

If the names are right, then I suspect that the system is NOT reading ~/.xinitrc at boot or you've entered the command incorrectly.

Answer 2

Putting xrandr commands in .xinitrc is not a proper way to store permanent settings. You should use xorg.conf instead.

So start from removing the xrandr lines from your .xinitrc, and then create (or edit) an /etc/X11/xorg.conf file. It should look exactly like this (no more content is needed unless you want to configure keyboard, mouse or similar devices):

Section "Monitor"
     Identifier "First monitor"
     Option     "PreferredMode"   "1280x1024"
EndSection

Section "Monitor"
     Identifier "Second monitor"
     Option     "PreferredMode"   "1680x1050"
     Option     "LeftOf"          "First monitor"
EndSection

Section "Device"
    Identifier  "Radeon X1300"
    Driver      "radeon"
    Option      "Monitor-DVI-0"   "First monitor"
    Option      "Monitor-DVI-1"   "Second monitor"
EndSection