gistfile1.txt

johannes@jd2:~ % xrandr --newmode "1024x768_50.00" 52.00 1024 1072 1168 1312 768 771 775 793 -hsync +vsync
johannes@jd2:~ % xrandr --verbose --addmode eDP-1 "1024x768_50.00"
johannes@jd2:~ % xrandr --output eDP-1 --mode 1024x768_50.00
johannes@jd2:~ % xrandr -q
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 8192 x 8192
eDP-1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 309mm x 174mm
   1920x1080     60.02 +  47.99  
   1400x1050     59.98  
   1280x1024     60.02  
   1280x960      60.00  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   800x600       60.00    60.32    56.25  
   700x525       59.98  
   640x512       60.02  
   640x480       60.00    59.94  
   512x384       60.00  
   400x300       60.32    56.34  
   320x240       60.05  
   1024x768_50.00  49.98* 
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
johannes@jd2:~ % glxgears
Running synchronized to the vertical refresh.  The framerate should be
approximately the same as the monitor refresh rate.
301 frames in 5.0 seconds = 60.019 FPS
301 frames in 5.0 seconds = 60.021 FPS
301 frames in 5.0 seconds = 60.022 FPS