Unhappy with the unreasonably large text on my 1920x1080 external screen connected to a laptop with a 3200x1800 display in Fedora 24, I tried rescaling the external screen by using:
xrandr --output HDMI-2 --scale 2x2 --mode 1920x1080 --fb 7040x2160 --pos 0x0
xrandr --output eDP-1 --scale 1x1 --pos 3840x0
This has the desired effect, but it causes the cursor to flicker when I move the mouse on the laptop screen. The cursor does not flicker when it is on the external screen. Flickering stops when I revert to 1x1 scaling on the external screen:
xrandr --output HDMI-2 --scale 1x1 --mode 1920x1080 --fb 4120x1800 --pos 0x0
xrandr --output eDP-1 --scale 1x1 --pos 1920x0
How can I stop this flickering?