New PC switches to 150% scaling (DPI) when duplicate mode is selected with SMART display panel

[Hoyt]

Howdy all,

 

Found a weird deal yesterday I wanted to run by y'all.  I had to replace an all in one PC with a workstation with a dedicated GPU for a vocational teacher to run AutoCAD.  He has a SMART display panel as his secondary display.  GPU is an Nvidia Quadro.

 

When he is in extended mode or PC only scaling is at 100% as it should be.  For some reason when he selects duplicate mode stupid Windows 11 thinks the panel is a TV and sets scaling for both his monitor and the SMART panel to 150%.  Since teachers do not have admin rights he cannot adjust this.  I can log in as myself and set it to 100% but that setting does not appear to be global.  As soon as another user logs in and selects the duplicate display mode it bounces to 150% scaling and nothing fits on the screen properly.  AutoCAD refuses to launch (rightly so) because the scaling is messed up.  His old PC was an all in one with integrated video and this problem did not exist (that machine was Windows 11 also, but had just recently been upgraded from Windows 10).

 

I have found an open source utility called Set DPI that will force anyone's login session to 100%, but I was hoping to find an "officially supported" method to ease the stress on my superiors.

 

What say y'all?  Anyone encountered this before?

[Rob_D]

We had a similar problem back in Windows 10 (it's windows trying to be helpful and upping the DPI scaling because it detects a high resolution screen).

We fixed it with a registry edit. Create a  hex dword key called LogPixels with a value of 96 in "\HKEY_USERS\.DEFAULT\Control Panel\Desktop". But this was 10 odd years back and I think switching between extend and duplicate might have broken it again so YMMV.

 

 

[flipthebit]

We have 4K IWBs connected to 1080p screen PCs. They also switch scaling in the same manner. I believe it's certain properties of the 'better' screen that automatically dictates what scaling is set.

[Hoyt]

This tool here works:

 

SetDPI

 

So if anyone is at a complete loss that could be used.  I'll try the registry settings but I've read they may not work with current builds.