I have a triple monitor setup. I know all three monitors work and are plugged in. However on Fedora 23 my primary and secondary monitors mirror each other and my third monitor just on sleep and doesn't receive any signal. I am using a Radeon R9 390 8GB GPU. Primary monitor is hdmi. Secondary and third monitors are using DVI. Here is the output of xrandr:
xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 480, current 1920 x 1080, maximum 1920 x 1080 default connected primary 1920x1080+0+0 0mm x 0mm 1920x1080 0.00* 1280x1024 0.00 1024x768 0.00 800x600 0.00 640x480 0.00
Looking around the internet I found this command and it looks like its giving some good info? Not too sure.
[bowen@dehd ~]$ lspci -nnk | grep -iA2 vga 02:00.0 VGA compatible controller : Advanced Micro Devices, Inc. [AMD/ATI] Hawaii PRO [Radeon R9 290] [1002:67b1] (rev 80) Subsystem: Tul Corporation / PowerColor Device [148c:2358] Kernel modules: radeon [bowen@ehd ~]$ lspci -nnk | grep -iA2 hdmi 02:00.1 Audio device : Advanced Micro Devices, Inc. [AMD/ATI] Hawaii HDMI Audio [1002:aac8] Subsystem: Tul Corporation / PowerColor Device [148c:aac8] Kernel driver in use: snd_hda_intel
I want to have three monitors with extended display but I do not know enough to accomplish this.