I'm updated fully as of today under 20.04 and have the same issue described in OP with an NVIDIA M2000M in a Thinkpad P50 using the proprietary drivers and 1 1080p monitor (the laptop panel) and 1 4k monitor (Dell external).
#83 indicated that they changed things so that their PRIME settings were "on demand" and that made things work for them, but my external monitor just quits working when I change it to that. Things work mostly as expected with the nouveau driver, but no scaling really works under the proprietary driver. I would use the nouveau driver but it seems very sluggish under any scaling factor. That said, my issue isn't really about fractional scaling, FWIW. I want to set the external display at 200% and set the internal one at 100%, a configuration which doesn't require fractional. But doing this produces 200% on both panels reliably (and the percentage values in settings reflect that both are set to 200%) under the proprietary drivers. So right now I can effectively either choose from these three options: a) use nouveau, make both displays work as I would like, but have a very sluggish UI experience b) use proprietary and have text that's too small to read for my old eyes on the 4K external monitor but have a usable built-in display, or b) use proprietary to get reasonably sized text and icons on the 4K external monitor but accept that the built-in monitor is not very useful because its effective resolution is 960x540. It seems that some people have gotten the combination of proprietary NVIDIA drivers and scaling to work. I would try this on another system to doublecheck but I don't have a machine handy with NVIDIA graphics different than the one in my system (M2000M). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1870736 Title: [nvidia] Screen scaling 125% gives 200% To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1870736/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs