I am using a computer equipped with the GeForce GT 640 card, featuring one VGA port, two DVI ports and one HDMI port. For a long time, I have been using a single monitor plugged into the VGA port and it has worked fine.
I recently got a second monitor, which I plugged into the DVI port. For various reasons, I would like to keep my original monitor (on the VGA port) as the primary monitor. When I booted linux, the new monitor on the DVI port had, however, become the primary monitor. I tried to change this by going to Systems->Settings->Settings->Monitors, but was met with the message "could not get screen information". Note that this is translated to English, and might not be completely accurate.
How might I address this problem? Also, if would be happy to learn how to change screen/monitor settings from the command line.
Specs:
*Debian: version 8.5
*Kernel: 3.16.0-4-amd64
*Gnome: GNOME Shell 3.14.4
/etc/X11/xorg.conf
exists and is non-empty, check what is under Driver.Section "Device" -> Driver "nvidia"
. You could also look at/var/log/Xorg.0.log
to check what driver is being loaded. I normally recommend people using the proprietary Nvidia drivers, though I'm not a fan of proprietary software. But in the case of Nvidia cards, it generally is the better choice. – Faheem Mitha Jun 17 '17 at 12:31