I have a system set up with two NVidia cards:
- a GTX 1070 - main, used when booting
- a GTX 750 Ti card
They are both connected to the same monitor - a Dell U2515H. The 1070 is connected to the mini display port, while the 750 Ti is connected to the HDMI port.
I have tried the following:
- Boot using 1070
- Log in to Gnome
- Start a second Xorg instance using the 750Ti using a custom script
The script is below
sudo strace Xorg :2 vt8 -config xorg-second.conf -configdir
I’ll attach the xorg-second.conf file shortly. The conf.d directory is empty, I’ve passed it to try and prevent other config files from being processed.
The result is that the monitor receives no signal via HDMI. More annoying, certain operations seem to hang the second Xorg instance. For example, running
xrandr --display :2
once works, but the second time it hangs.
The same setup works with Windows, I’ve booted a Windows 8.1 from an external drive and output is sent via both video cards.
What do I have to do to enable the second video card?