Add new resolution for Linux Mint / Ubuntu

jarvis@linuxmint ~ $

xrandr

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 8192 x 8192

VGA1
connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm

1024x768 60.0*

800x600 60.3 56.2

848x480 60.0

640x480 59.9

jarvis@linuxmint ~ $ gtf 1680 1050 59.9

# 1680x1050 @ 59.90 Hz (GTF) hsync: 65.11 kHz; pclk: 146.89 MHz
Modeline "1680x1050_59.90" 146.89 1680 1784 1968 2256 1050 1051 1054 1087 -HSync +Vsync

jarvis@linuxmint ~ $ xrandr --newmode "1680x1050_59.90" 146.89 1680 1784 1968 2256 1050 1051 1054 1087 -HSync +Vsync

jarvis@linuxmint ~ $ xrandr --addmode VGA1 1680x1050_[b]59.90[/b]

Then you can choose in the display settings.

To make this valid when next login, add the xrandr commands to .profile:
xrandr --newmode "1680x1050_59.90" 146.89 1680 1784 1968 2256 1050 1051 1054 1087 -HSync +Vsync
xrandr --addmode VGA1 1680x1050_59.90