I have an ATI HD5770, connected to 2 monitors(DVI and DisplayPort).
When booting up ArchLinux the TTY display is duplicated between the two monitors as excepted, but when starting the X server(Awesome WM) I'm stuck with only one monitor, while the other one is going to power save mode(black screen).
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192 DisplayPort-0 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm 1024x768 60.00* 800x600 60.32 56.25 848x480 60.00 640x480 59.94 HDMI-0 disconnected (normal left inverted right x axis y axis) DVI-0 disconnected (normal left inverted right x axis y axis) DVI-1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm 1680x1050 59.95*+ 1280x1024 75.02 60.02 1440x900 74.98 59.89 1024x768 75.08 70.07 60.00 800x600 72.19 75.00 60.32 640x480 75.00 72.81 60.00 720x400 70.08
The resolutions on the DisplayPort are also incorrect.
I've tried so many xrandr command combinations, nothing changed the fact that the DisplayPort connected monitor is inactive.
It's probably worth mentioning that I'm using xf86-video-ati and on Windows(dual boot) I've got no problem with the monitors.
Before that I've also needed to disable Fast Boot from the UEFI configuration tool to be able to actually see the TTY on both monitors.