DPI scaling not working in remote session
I got a new laptop with a screen resolution of 2560x1600. This requires DPI scaling set to 130% to be able to read text on the built-in screen.
RDM version 2026.1.14.0 64-bit (PreJIT)
When starting a RDP session to a Windows server, this scaling is not inherited into the remote session - so very small font.
I tried the steps from this document:
https://docs.devolutions.net/rdm/kb/troubleshooting-articles/high-dpi-issue/
but no effect. I can't get DPI scaling to work in the remote sessions.
I just didn't get the part about the CFG file in that document, that part doesn't seem complete.
So situation:
- shortcut for RemoteDesktopManager.exe has configured 'override high dpi scaling'= application
- DirectX disabled in RDM
- Settings/Entry types/Sessions/RDP, 'disable RDP scale factor' is UNCHECKEDSettings/
- Settings/Hardware accelartion = DISABLED (otherwise still DirectX active)
- Properties of RDP session: Display, Screen sizing mode=Smart Reconnect, Remote Desktop size=Default (Automatic)
What are 'the' steps to achieve inherited DPI scaling in a remote session??
All Comments (5)
Hello,
RDM cannot control or enforce DPI scaling inside remote sessions this is handled by the RDP protocol and the remote Windows system.
That’s why your local scaling (130%) isn’t applied in the session.
You’ll need to adjust scaling directly on the remote machine or use a lower resolution in the RDP settings.
Hello.
Carl Marien
That is too bad. In a Windows remote session, scaling or resolution cannot be changed. I will look for alternatives then.
Hello
What my colleague wrote isn't entirely accurate, but it's also not a setting exposed directly in either RDM or mstsc.
The client hints to the server the DPI scaling that it wants on the remote session. This is interpreted from the local display scaling on your client (RDM) machine. Arbitrary values aren't accepted, so you won't get 130%, the scale factors available are restricted (e.g. 150%, 175%, 200% and so on).
Older versions of Windows server have a registry key that can be set that instructs the server to ignore the client side scaling hint. Modern versions of Windows server ignore this key and always use the hint from the client. I would need to check exactly what version of Windows that applies to.
So - this should be working in your environment. Can you confirm two things:
- What's the version of Windows on the affected server? Is it just this server that it isn't working, or others?
- What's the result when you connect directly using Microsoft Remote Desktop (mstsc.exe)? Is it scaled as you expect with the default settings?
Thanks and kind regards,
Richard Markievicz
Hello Richard,
thank you for your additional reply!
As a consultant I connect to a variety of servers.
I think the remark ".. scale factors available are restricted (e.g. 150% .." hit the spot.
I changed the scaling factor from 130% to 150% on my laptop and tried connecting to a few different servers, and they all scaled as well !
This seems to solve my problem, thanks!
Hello
I'm glad that's working for you, but possibly this is a bug.
RDM is mapping scale factors 1:1, meaning if you have 125% locally, that is what is sent to the server. Same for all the allowed factors (125, 150, 175, 200) etc...
What this doesn't account for is in your case, where you have a custom scale factor locally. It will always be resolved to 100%. So in your specific example, where you have 130% locally that should probably be rounded down to 125%.
I will open a ticket to take a look at this. I need to check what Microsoft does here (do they round to the closest scale factor) or possibly RDM needs the capability to allow the user to choose what scale factor they want.
Thanks and kind regards,
Richard Markievicz
