Thank you, both sunbearc22 and birdie for providing help! birdie’s method works for me, except that for Linux 16.04, I should create the file in another directory: /usr/share/X11/xorg.conf.d/nvidia.conf
You can use either. /usr/share/X11/xorg.conf.d is for system software to install pieces of configuration data, and /etc/X11/xorg.conf and /etc/X11/xorg.conf.d/ are for the system administrator’s configuration files.
If you put your configuration files in /usr/share/X11/xorg.conf.d, you run the risk of them being overwritten by the package manager. Although the risk of that is probably small. :)
There’s a list of places the server looks for configuration files in the xorg.conf(5) man page.
Thank you Moderator! I see what you mean. However, Ubuntu 16.04 don’t have xorg.conf nor xorg.conf.d/ under the directory /etc/X11. Shall I mkdir /etc/X11/xorg.conf.d, and create the file /etc/X11/xorg.conf.d/nvidia.conf ?
I have the same issue as the original poster, but the solution given here does not work for me. I am running Linux Mint 18.3 which is based on Ubuntu 16.04. My Nvidia driver version is 384.130. I have two GTX1080’s (GPU0,GPU1) and one GT620 (GPU2) installed in an Asus X299 motherboard. I want to use the GT620 for display and the GTX1080’s for CUDA computing. I tried adding the BusID line for the GT620 (in decimal and hex) to both /etc/X11/xorg.conf and /usr/share/X11/xorg.conf.d/nvidia.conf. BIOS ignores the change and Linux Mint will not start at all. Nothing ever comes out of GPU2. Has something changed in the past year and a half that would require a different solution? nvidia-bug-report.log.gz (213 KB)
Is there a way that I can use my 2nd GPU for display while having coolbits enabled on my 1st GPU for fan control? In order to enable manual fan control I need to explicitly enable coolbits on X11/xorg.conf for my 1st GPU but doing that will make Linux use it for display instead of my 2nd GPU.