xrandr 
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 1280 x 1280
VGA connected 1280x1024+0+0 (normal left inverted right) 338mm x 270mm
   1280x1024      60.0*+   75.0     59.9  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0     59.9  
   832x624        74.6  
   800x600        72.2     75.0     60.3     59.9     56.2  
   640x480        75.0     72.8     66.7     60.0  
   720x400        70.1  
LVDS connected 1280x800+0+0 (normal left inverted right) 286mm x 179mm
   1280x800       59.9*+   60.0  
   1280x768       60.0  
   1024x768       60.0  
   800x600        60.3  
   640x480        59.9  
TMDS-1 connected (normal left inverted right)
   1280x800       60.0  
   1280x768       60.0  
   1024x768       60.0  
   800x600        60.3  
   640x480        59.9  
TV disconnected (normal left inverted right)


 xrandr --output VGA --mode 1280x1024