DPI Scaling Fix for Ubuntu on HiDPI 3840x2160 eDP1 with two 1920x1080 External Monitors

sh

#!/bin/bash

# Assumes that our global DPI default is for the Highest Resolution Monitor

# --scale 2x2:       Our external monitor scale is 2x of our 4K monitor.
# --output <Name>:   Just run xrandr without arguments to list device names.
# --mode:            The supported mode of the --output monitor.
# --fb:              1920 * 2 x 1080 * 2 + 1080, or 3840x3240. Sets this monitors to fit this space.
# --pos:             Set my external monitor locations starting at 0x0
xrandr --output DP-2 --scale 2x2 --mode 1920x1080 --fb 3840x3240 --pos 0x0
xrandr --output DP-1 --scale 2x2 --mode 1920x1080 --fb 3840x3240 --pos 3840x0
# --scale 1x1:       Our laptop monitor is equal to our global DPI setting.
# --pos 960x2160:    Move our screen down so it does not overlap the external monitor. (1920 * 2 - 1920) / 2 x 1080 * 2, or 960x2160
xrandr --output eDP-1 --scale 1x1 --pos 960x2160
# results in the following layout of monitors. Maximizing and minimizing on each desktop works.
# [  ]  [  ]
#   [    ]

UbuntuHiDPI.md

Based on the contents http://blog.jamiek.it/2015/04/manually-fixing-multiple-screens-with.html

• Set your Ubuntu to the highest DPI from the System Configurations
• If not using Ubuntu, then you may need to configure based on instructions here and use a DPI calclator.
• Please referer to the full blog post and give thanks to the OP.
• This is just notes and a cached script for my personal laptop
• I have two external monitors (DP-1 and DP-2) sitting to the top left and top right of my laptop screen (eDP-1)