ArchiCAD 21 is not quite ready for 4K display. However, I am using ArchiCAD 21 with my 17.3" laptop screen at 3840x2160 anyway. There are a few problems with doing this, but to me the crystal clear screen is worth it. I have to stretch some windows to see what I need. I don't think it will be too long until ArchiCAD is compatible with 4K display.
It's hard to show what this looks like because screen a screen capture just doesn't do it justice. But ArchiCAD looks fantastic at 3840x2160/razer sharp once you get the display settings correct.
I use a 25'' monitor at 2560x1440 and for me it's the best compromise right now in terms of resolution, size of the monitor and cost.
The experience is great for me.
However you should read an interesting post published here in the forum about the monitor size and resolution ... maybe it is helpful in your choice.
ArchiCAD has no issues with HiDPI on MacOS and scales well on 4K screens, Windows 10 however deals with HiDPI screens atrociously ArchiCAD is OK (much better than the Autodesk suite of software) but there are still some annoying issues with regards to cursor size
... Windows 10 however deals with HiDPI screens atrociously ArchiCAD is OK (much better than the Autodesk suite of software) but there are still some annoying issues with regards to cursor size
Not for me. I have no issues at all with the cursor or its size, and I have never seen any problems like that using Windows 10. ArchiCAD looks amazing and functions well enough on my 17.3" Ultra High Definition IPS laptop screen at 3840x2160. This screen is as good as it gets I think. Perhaps it's my awsome graphics card ? If I could afford them, my card will support (4) 4K screens or (2) 8K screens. I think I might be using the ultimate Mobile Workstation. I love it.
It's a little ahead of ArchiCAD now, but not for long.
Issues I find are in now way performance related it’s more to do with inconsistent UI display issues accross the operating system (Win 10 Pro64 latest release) as programs all seem to address graphics differently (ie all graphics calls are not via operating system but some are directly to the driver), this is apparent in AutoCAD where some elements scale according to the system display scaling and others do not. On a 4K 15.4 inch dream colour monitor inconsistencies really annoy me. No problems however on my MacBook Pro as all graphics handled by the OS.