bash-4.3# xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 480, current 1280 x 1024, maximum 1280 x 1024
default connected 1280x1024+0+0 0mm x 0mm
   1280x1024      0.00*
   1024x768       0.00
   800x600        0.00
   640x480        0.00

bash-4.3# xrandr -s 1680x1050
Size 1680x1050 not found in available modes
bash-4.3#

my device (samsung) supports 1680x1050 resolution. there is no xorg.conf to be changed

2015-01-18 22:49 GMT-02:00 Bryan Bennett <bbenne10@gmail.com>:

What is output by `xrandr --verbose`? If EDID information is
being reported properly, it should show you the possible
resolutions for your monitor (presumably containing
1680x1050, since that's what you're expecting.) if not,
It may be that your EDID information is goofed and you need
to tell Xorg to augment that information with more resolutions
by adding modelines to your Xorg.conf (or however the hell it's
supposed to be done now)

Cezar Rangel

cezar.rangel@gmail.com