Add missing Monitor Resolution profile

Add missing resolution setting for Acer ASpire 5742 (1366x768) to be used with a 24" Dell P2414H capable of FHD resolution (1920x1080)

Edit on GitHub
Jan 21, 2019
Linux
2 minutes

tl;dr

get Modeline cvt 1366 768
create and add new mode with xrandr based on the generated modeline
add settings to ~/.xprofile to preserve them, so the settings are still there when you restart

1# Add 1366x768@60Hz
2xrandr --newmode "1368x768"  85.86  1368 1440 1584 1800  768 769 772 795  -HSync +Vsync
3xrandr --addmode VGA-1 1368x768
4xrandr --output VGA-1 --mode 1368x768

get Modeline

1cvt 1366 768

1# 1368x768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz
2Modeline "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync

create and add mode

1# Add the resolution supported by Acer Aspire 5742 on VGA port
2xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync
3xrandr --addmode VGA-1 1368x768_60.00

1# find the monitor identifier to set the mode for
2xrandr --listmonitors

Monitors: 2
 0: +*LVDS-1 1366/344x768/194+0+0  LVDS-1
 1: +VGA-1 1024/271x768/203+1366+0  VGA-1

set output mode

1xrandr --output VGA-1 --mode 1368x768_60.00

create .xprofile

Create a ~/.xprofile file and simply add the commands for the programs you wish to start with the session

1touch ${HOME}/.xprofile
2echo "
3# Add the resolution supported by Acer Aspire 5742 on VGA port
4xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync
5xrandr --addmode VGA-1 1368x768_60.00
6xrandr --output VGA-1 --mode 1368x768_60.00
7" >> ${HOME}/.xprofile

Troubleshooting

if the resolution is not working, try changing the frequency. You can specify the frequency when getting modeline with the gtf command

1gtf 1366 768 30 -x

1# get video controller details
2sudo lshw -C video

Notes