xrandr shows you the names of different outputs available on your system (LVDS, VGA-0, etc.) and resolutions available on each:
$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
DVI-I-1 disconnected (normal left inverted right x axis y axis)
DVI-I-2 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
1280x1024 60.0*+ 75.0
1280x960 60.0
1280x800 74.9 59.8
1152x864 75.0
1280x768 74.9 59.9
1024x768 75.1 70.1 60.0
1024x576 60.0
800x600 72.2 75.0 60.3 56.2
848x480 60.0
640x480 72.8 75.0 60.0
720x400 70.1
TV-1 disconnected (normal left inverted right x axis y axis)
Set a different resolution:
# xrandr --output DVI-I-2 --mode 1280x960
