I have an old dual G5 powermac with an nvidia graphics card that I’m building up for a YDL 6.0 development box. The problem I was having was that regardless of the resolution I set my display to, I was always getting a 1440×900 @ 54Hz desktop.
The solution turns out to be relatively simple. So, if you too are stuck with an ill-fitted desktop here is how to fix it:
1. Log in and open a terminal window (or press <CTRL+ALT+F2> if you can’t see your desktop)
2. edit the file /etc/X11/xorg.conf
[billdar@mr-blue ~]$ vi /etc/X11/xorg.conf
3. scroll down and find the Device section. press “i” to start editing and add the following line:
Section “Device”
Identifier “Card0″
Driver “nv”
Option “HWCursor” “true”
Option “ModeValidation” “NoEdidDFPMaxSizeCheck”
EndSection4. Press <ESC> to exit edit mode, then type “:wq” to save and quit
5. Restart X by either rebooting or pressing <CTRL+ALT+BACKSPACE>
That should fix it. Now you can use the display utility to set your desired resolution.