Using 2 video cards and 3 monitors

Question

Im trying to get 3 screens working, one on my onboard AMD HD4200 and 2 on my Nvidia GT 430. I am getting 2 screens working, but I X is giving me an error. It says "Screen 1 was deleted because of no matching config section" Any Ideas?

Also, I can not use a tool like arandr because it does not recognize all of the monitors/devices.

Here is my xorg.conf:

#Section "ServerFlags"
#       Option  "xinerama"      "True"
#EndSection

Section "ServerLayout"
        Identifier     "X.org Configured"
        Screen      0  "MidScreen" 0 0
        Screen      1  "LeftScreen" LeftOf "MidScreen"
        Screen      2  "RightScreen" RightOf "MidScreen"
        Option  "Clone" "Off"
EndSection

#-------------------------------------------------------------------$


Section "Device"
        Identifier  "Nvidia-dvi"
        Driver      "nouveau"
        BusID       "PCI:2:0:0"
        Option  "ZaphodHeads"   "DVI-I-1"
        Screen  1
EndSection

Section "Device"
        Identifier  "Nvidia-vga"
        Driver      "nouveau"
        BusID       "PCI:2:0:0"
        Option  "ZaphodHeads"   "VGA-0"
        Screen  2
EndSection

Section "Device"
        Identifier  "ATI"
        Driver      "vesa"
        BusID       "PCI:1:5:0"
        Screen  0
EndSection


#-------------------------------------------------------------------$


Section "Monitor"
        Identifier      "LeftMonitor"
EndSection

Section "Monitor"
        Identifier      "MidMonitor"
EndSection

Section "Monitor"
        Identifier      "RightMonitor"
EndSection


#-------------------------------------------------------------------$


Section "Screen"
        Identifier "LeftScreen"
        Device  "Nvidia-dvi"
        Monitor "LeftMonitor"
EndSection

Section "Screen"
        Identifier "MidScreen"
        Device  "ATI"
        Monitor "MidMonitor"
EndSection

Section "Screen"
        Identifier "RightScreen"
        Device  "Nvidia-vga"
        Monitor "RightMonitor"
EndSection

Answer 1

I may be mistaken but if you combine discrete graphics with onboard, i think the onboard gets disabled, did you check its still enabled in bios? To be honest, your asking for trouble combining graphic solutions like that, especially when they are a combination of both AMD and NVIDIA products (unless you have a lucid chip of course).

If you are dead set on having a tri-screen setup, my advice to you would be to find a suitable graphics card with enough inputs to meet your needs.

Answer 2

I thought I lost a graphics card, so I wanted to take advantage of my integrated graphics with TWO DVIs. Why buy new hardware when I have not fully utilized the onboard, especially for auxiliary monitors that will never see a graphics intense application. Unfortunately, this seems to be highly non-trivial.

I did not get it working, eventually realized my lack of ground in a 3 prong outlet that looked grounded was causing power supply failure and the GPU was fine, so take for what it's worth.

I had to:

BIOS: force integrated: True (basically don't shut it off if discrete graphics detected, since you want both)

Startup: GRUB: will probably need to adjust something, I think I tried setting this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nogpumanager"

and/or

GRUB_CMDLINE_LINUX_DEFAULT="xdg.force_integrated=1"

with required

sudo update grub (ubuntu)

sudo grub2-mkconfig (RHEL/centos/fedora)

which is actually targeting /boot/grub2/grub.cfg

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

sudo grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg

or generally

sudo grub2-mkconfig -o $(readlink -f /etc/grub2-efi.cfg), or no efi for BIOS system

There probably would be some required config with xorg, xrandr, etc. and familiarity with the following commands might help:

systemctl restart display-manager (to restart GDM) lspci (to verify hardware detected) lshw xrandr --listproviders xrandr -q

Also as last resort you may want to install nvidia proprietary drivers (at least for the nvidia card), which may offer additional commands:

nvidia-settings
nvidia-prime
nvidia-current
nvidia-xconfig

to generate config files,etc.