Ask HN: How well are 4k monitors supported under Linux?

I really wanted to cry when I saw what a 4K monitor did to my KDE4 desktop... - It is much worse than I expected and not even remotely close to being finished: https://community.kde.org/KDE/High-dpi_issues

I have a 4k monoprice monitor. It works just great under ubuntu 14.04LTS with a Geforce 960 and the tested nvidia blob driver. Ubuntu allows 1.5x window title scaling, made things nicer.

Pretty good from what I've seen. I've been using one for the last year. One notable thing is that if you're using more than one monitor, you might have issues if they have different resolution (it's unlikely you can do 2x 4K monitors). It's rather tedious to get X + your WM to run two different DPI on the two screens. I ended up having to run two X servers for two monitors, which has its own limitation.

Depends. I've had a Samsung U28D590D (http://www.samsung.com/us/computer/monitors/LU28D590DS/ZA) since October 2014 with a Radeon HD 7970. Only until kernel versions 4.2-4.3 and xf86-video-ati 1:7.6 have I been able to get the DPMS to properly activate. It was maddening having to ssh and and play the prod the DPMS state until the monitor flickers back on. However, I quickly gave up on any HiDPI and desktop environments and stuck with xmonad. Works like a charm now.

It isn't a 4k issue as much as neither GTK3 nor QT5 wants to really make any effort to force adoption of DPI-aware code, unlike what, say, Android and iOS and Windows 10 has done, which is to force apps to have layouts specific for certain device sizes and also be HiDPI aware, with OSX not doing specific layouts but still requiring HiDPI awareness.

Amusingly enough - old school tiling wm manager setups like dwm work best on retina screens. I really enjoy using dwm on a retina display with crisp tiled emacs windows.