DPI scaling is way off on KDE/Plasma

Graphics / Linux Linux
1

This is a bug report related to NVidia proprietary drivers. All the information and comments is here:

DPI scaling is way off when using nvidia proprietary drivers instead of nouveau

Summary: fonts and UI is bigger than should be.

2

What are the actual physical dimensions of the display? Those size numbers are taken directly from the EDID and the DPI is computed from that.

3

Screen size is 17.3" FHD.

4

That isn’t what he wants, post the output for

xdpyinfo |grep -e resol -e dim

$ xdpyinfo |grep -e resol -e dim
  dimensions:    3840x2160 pixels (1016x571 millimeters)
  resolution:    96x96 dots per inch
6

Here you have it.

$ xdpyinfo |grep -e resol -e dim
  dimensions:    1920x1080 pixels (381x211 millimeters)
  resolution:    128x130 dots per inch
7

That looks correct for a 17.3" display. Nouveau is likely just returning 96 DPI instead of calculating it from the monitor EDID. See: DPI from the README. You can set it to ignore the EDID and force it to 96 DPI in the xorg.conf/xorg conf.d.

The problem with clipping in the screenshots you show are bugs in those programs. They aren’t handling hidpi displays correctly.

8

Since the nvidia driver and card firmware are closed source, I cannot know for sure if the issue is on Nvidia’s side, which is from my understanding.