How to force a higher screen resolution from Ubuntu 12.04 and an NVidia GTX460?
Solution 1:
I finally found a solution - an Edid for my Shimian QH270-Lite here thanks to someone who had the same problem with another Korean 2560x1440 monitor, the Yamakasi Catleap.
I installed the new Edid following instructions posted at ubuntuforums.org, thread 1857772 - sorry I can't post more than two links:
Create an NVidia xconf file with the new edid:
$ sudo nvidia-xconfig --custom-edid=/etc/X11/Shimian_edid.bin
Check your Xorg log for Display Device Name - probably DFP-0, or DFP-1:
cat /var/log/Xorg.0.log | grep connected
which should bring up something like:
(--) NVIDIA(0): *Your_monitor's_name* (DFP-0) (connected) in which case your Display Device Name is DFP-0
Check and if necessary correct xconf: sudo gedit /etc/X11/xorg.conf
Look for a line like:
Option "CustomEDID" "/etc/X11/Shimian_edid.bin"
and edit it to read:
Option "CustomEDID" "DFP-0:/etc/X11/Shimian_edid.bin"
Reboot and at last the monitor works at 2560x1440 as intended.
If that hadn't worked, Plan B was to build a custom configuration following NVidia's Xconfig options (in the README file for the 310.19 Linux driver from NVidia's downloads), in particular the "CustomEDID" option.
Thanks to the contributors to the links above and hopefully this will help someone else with the same problem.