Nvidia on FreeBSD

[moridin at mm.st]

James B. Byrne via freebsd-questions wrote:
> FreeBSD-12.1p8
> 
> I am forced to configure a new workstation (WS) due to an unrecoverable
> hardware error on my old (c.2009) one.  The new WS has only basic VGA on the
> motherboard and has an Nvidia card as its primary video i/f.
> 
> I have two monitors both connected to the card.  Each works independently of
> the other but when both are connected only one display is used.
> 
> I have the Mate desktop installed and working.  However when I try to configure
> the monitors the display dialogue window only shows one, unknown, display and
> the detect monitor button is not active.  I also get a message stating that the
> mate-settings-daemon cannot start.
> 
> I need some help getting this sorted out.  If someone could guide me through
> this I would appreciate it very much.

I know nothing about mate and its settings, but I remember running X on 
dual-monitor setup with nvidia.  What you need is to get the output 
names from Xorg.log in /var/log (e.g. DFP-0, DFP-2) and add relevant 
config line to your /usr/local/etc/X11/xorg.conf.d/<name>.conf, e.g.:

Section "Device"
	Identifier	"Something here"
	Driver		"nvidia"
	MetaModes	"DFP-0:3840x2160,DFP-2:3840x2160"
EndSection

Check the documentation shipped with nvidia-driver for more options.