Ich poste mal meine xorg.conf, in der Hoffnung, dass irgendjemand mal googelt und es nützlich findet. Es waren einige Tage Gefummel.

Wenn man das radeon Kernel Modul nutzt und mehrere Monitore im portrait mode (also hochkant rotiert) haben möchte und dabei auch noch mehrere Grafikkarten nutzt, dann sieht das wie folgt aus.

Mit Xinerama-Unterstützung wird sich dass dann möglicherweise aufhängen. Aber wenn man einen Tiling Window Manager nutzt, braucht man auch kein Xinerama. Cheers!

Meine xorg.conf

Section "ServerLayout"
Identifier "iblue Layout"
Screen 0 "Screen-0" 0 0
Screen 1 "Screen-1" RightOf "Screen-0"
Screen 2 "Screen-2" RightOf "Screen-1"
Screen 3 "Screen-3" RightOf "Screen-2"
EndSection

Section "ServerFlags"
Option "RandR" "false"
EndSection


Section "Module"
Load "dbe"
Load "dri"
Load "extmod"
Load "dri2"
Load "record"
Load "glx"
EndSection

Section "Monitor"
Identifier "Monitor-0"
Option "Rotate" "left"
EndSection

Section "Monitor"
Identifier "Monitor-1"
Option "Rotate" "left"
EndSection

Section "Monitor"
Identifier "Monitor-2"
Option "Rotate" "left"
EndSection

Section "Monitor"
Identifier "Monitor-3"
Option "Rotate" "left"
EndSection

Section "Device"
Identifier "Radeon-0-0"
Driver "radeon"
BusID "PCI:9:0:0"
Option "ZaphodHeads" "DVI-0"
Screen 0
EndSection

Section "Device"
Identifier "Radeon-0-1"
Driver "radeon"
BusID "PCI:9:0:0"
Option "ZaphodHeads" "DVI-1"
Screen 1
EndSection

Section "Device"
Identifier "Radeon-1-0"
Driver "radeon"
BusID "PCI:4:0:0"
Option "ZaphodHeads" "DVI-2"
Screen 0
EndSection

Section "Device"
Identifier "Radeon-1-1"
Driver "radeon"
BusID "PCI:4:0:0"
Option "ZaphodHeads" "DVI-3"
Screen 1
EndSection

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

Section "Screen"
Identifier "Screen-1"
Device "Radeon-0-1"
Monitor "Monitor-1"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection

Section "Screen"
Identifier "Screen-2"
Device "Radeon-1-0"
Monitor "Monitor-2"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection

Section "Screen"
Identifier "Screen-3"
Device "Radeon-1-1"
Monitor "Monitor-3"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection