External Monitor only shows a quarter when scaling 2x2 on bumblebee setup (Intel + Nvidia Quadro M20...

Hello and thanks for checking out my problem.
I have a Lenovo ThinkPad P50 with a 4k (hidpi) display. The dpi settings are all properly set and my laptop screen is crisp and all is well. When connecting to an external monitor without hidpi things are logically quite large. To counteract this I’m applying --scale 2x2 in the xrandr initialization process.

These are the steps I take:

$ intel-virtual-output

this will turn on the nvidia card and make the display ports available as VIRTUAL devices for randr

$ xrandr --output VIRTUAL# --auto --scale 2x2 --right-of eDP1

this will only show the top right quarter of the virtual screen on the monitor, when applying --panning I can theoretically move over the whole window, but only top left is quarter is shown on the monitor.

$ xrandr -d :8 --output DP-# --auto --scale 2x2

this will put the correct size on the monitor but still only the top right quarter is visible while everything else is black. (see screenshot)
Google Photos

Also tried manually setting --fb with no success.

Thanks for your help.

nvidia bug report log:

Could anyone recommend me the best place to address my issue and ask for help? I thought this would be nvidia related but perhaps it’s not…

If you’re using Bumblebee, you are not using the nvidia driver. You will have more luck searching Arch documentation and asking there, I think.