Dual Monitor Not Working?

Kupenmen · 07-26-2015, 12:27 AM

I have installed Debian 8 (Jessie). I have two displays and only one seems to be working, or even recogized for that matter. One of my monitors is connected to my video card and the other is connected to my motherboard.

Code:

~$ lspci -nn | grep VGA
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GF114 [GeForce GTX 560 Ti] [10de:1200] (rev a1)

Code:

DVI-I-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
   1920x1080     60.00*+
   1600x1200     60.00  
   1680x1050     59.88  
   1400x1050     59.95  
   1600x900      59.98  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x960      60.00  
   1280x800      59.91  
   1152x864      75.00  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   640x480       75.00    72.81    66.67    60.00  
   720x400       70.08  
HDMI-3 disconnected (normal left inverted right x axis y axis)

How can I solve this?

TobiSGD · 07-26-2015, 03:36 AM

Many motherboards disable an inbuilt videocard when they detect a discrete videocard, this may be the case for you. Try if it works when you connect both monitors to the discrete videocard. Also, if that for some reason is not possible, search for an option to enable/disable the inbuilt videocard in your BIOS/UEFI firmware, it is probably disabled there.

273 · 07-26-2015, 05:32 AM

I agree with the above and will add that using the NVIDIA card for both screens is probably advisable as it will likely be a lot less problematic than trying to get both the onboard and discrete chips working and almost certainly perform better than trying to use both.