This is ordinarily the job of the display manager (your login thing) so you will want to check the configuration options for whichever one you use.
You can see what files are being loaded from the X log file usually located at /var/log/Xorg.0.log
. Check for the lines that look like this:
[ 39103.247] (++) Using config file: "/etc/X11/xorg.conf"
[ 39103.248] (==) Using config directory: "/etc/X11/xorg.conf.d"
Be sure to put your config files in the config directory with something like /etc/X11/xorg.conf.d/20-nvidia-settings.conf
.
I don't think Ubuntu uses the standard path. It is more likely located at /usr/share/X11/xorg.conf.d
.
You can change the files that are loaded with arguments to Xorg. From man xorg
:
-config file
Read the server configuration from file. This option will
work for any file when the server is run as root (i.e, with
real-uid 0), or for files relative to a directory in the con‐
fig search path for all other users.
-configdir directory
Read the server configuration files from directory. This
option will work for any directory when the server is run as
root (i.e, with real-uid 0), or for directories relative to a
directory in the config directory search path for all other
users.
Why would they not be loaded? They should. This is not an i3 problem.
@Michael, it does work when I don't use i3 (ubuntu 13).
@Mori, the settings in the xorg.conf are loaded completely before a window manager is started. The difference in behaviour between i3 and Unity is, that Unity tries to do its own auto-configuration while i3 does not. Have a look at /var/log/Xorg.0.log if any errors are reported.
Thanks @Adaephon, but there are no errors reported in /var/log/Xorg.0.log.