High resolution screen creates tiny icons and text with Mate desktop
For the MATE desktop, I finally found a solution. It is well hidden and hard to find, I think.
- Right-click on the desktop and choose Change Desktop Background OR: choose System -> Preferences -> Appearance.
- Choose the Fonts tab.
- Click the Details button.
- On the top of the dialog there is a Resolution entry field where you can enter or increase the DPI setting. Setting this to the true DPI of the display scales up everything too much, but with a little tinkering it is possible to find a good value.
Update 1: Under Gnome3, it is also possible to rescale the fonts by specifying a scaling factor in the gnome-tweak-tool. The gnome-tweak-tool also has a scaling factor for windows, but this only allows to specify integer value! So 1 is tiny and 2 is way too big!
Update 2: Cinnamon seems to be the only desktop manager which provides support for HiDPI out of the box! Everything is nicely scaled right from the start. Unfortunately, I had frequent problems with the display locking up or becoming unresponsive, so either it is not stable yet or it has issues with my specific hardware or configuration. But what Cinnamon has achieved is exactly what I would have expected for Unity, Gnome3, or KDE to do!
Update 3: Situation is even worse with a dual monitor setup: With Gnome3, the window manager that is the best compromise between stability and HiDPI support so far, dual monitor setup does not work at all: the login screen gets shown on both monitors, but as soon as I log into Gnome3, both screen flicker endlessly between a black screen and a switched off screen. If I unplug the second monitor everything is fine again. Under Unity the dual monitor setup works, but the scaling does not: windows on the second, lower resolution monitor are now too big, fonts are huge etc.