the problem was that, I made a fresh install of Ubuntu 14.04 on a Dell Optiplex 860 , with a AOC e943fws monitor that have a 1360x768 resolution at 60Hz.
The default configuration offers me only 1024x768 or 800x600 resolutions.
I spotted was possible to add the missing resolution with xrandr in this way.
give cvt with resolution and frequency
me@box:~$ cvt 1360 768 60
# 1360x768 59.80 Hz (CVT) hsync: 47.72 kHz; pclk: 84.75 MHz
Modeline "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
Then give xrandr --newmode omitting "Modeline" word on the command
It gives You no output.
me@box:~$ sudo xrandr --newmode "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
then add new mode to our current output , for me was VGA1
me@box:~$ sudo xrandr --addmode VGA1 1360x768_60.00
Now giving xrandr I obtain this output with the new resolution listed
me@box:~$ sudo xrandr
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 32767 x 32767
VGA1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x768 60.0*
800x600 60.3 56.2
848x480 60.0
640x480 59.9
1360x768_60.00 59.8
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
Now we can change the resolution
webstation1@webstation1:~$ sudo xrandr --output VGA1 --mode 1360x768_60.00
And for me that works fine.
At this point You will find the new resolution also in Monitor settings.
Bye
