Help With Multi-monitor Xorg Stuff

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I have an unusual use case. I wonder if anyone can help. We use a PC
with 8 HDMI outputs for powering a video wall in an operations centre. We use two Matrox video cards, each with 4 outputs. “lspci” reports these cards as” [AMD/ATI] Cape Verde PRO [FirePro W600]”.

On an older version of CentOS 7, I used the proprietary AMD/ATI
driver. This had a utility (I roorget the name) that generated a working xorg.conf file. I could them throw up the
“matchbox-window-manager” on each monitor in turn using
“DISPLAY=:0.0”, “DISPLAY=:0.1” etc and then throw up a full-screen chrome web browser in kiosk mode on each monitor after that. This all worked great.

In a recent version of CentOS 7, this all broke. The proprietary driver no longer works. The good news is that the open source driver seems to work fine with multi-monitor in Gnome for example.

My only issue is that I don’t want to use Gnome across multiple monitors. I want to use matchbox-window-manager or similar, and specify individual X screen (“:0.0”, “:0.1” etc). How do I generate an xorg.conf file with the new open source drivers? Am I doing this all wrong?

Thanks!

2 thoughts on - Help With Multi-monitor Xorg Stuff

  • Cracked this. The solution was that I needed to specify the correct driver (“radeon”) in the xorg conf file to use the open source driver, e.g.

    Section “Device”
    Identifier “aticonfig-Device[0]-0”
    Driver “radeon”
    BusID “PCI:1:0:0”
    EndSection

    All the other bits from the conf file I could keep the same as before.

  • I spoke too soon with this. I can’t get it to work properly with a hand-crafted xorg.conf file. As Gnome seems to automatically detect all the monitors OK, can anyone recommend a window manager I can use with CentOS 7 that will allow me to start independent full-screen kiosk browser sessions from a script, specifying which monitor to use each time?