As you might remember, IntelliJ IDEA 14.1 shipped with the initial HiDPI support for Windows and Linux which could be enabled via the -Dhidpi=true key in the idea.vmoptions file. The support was somewhat limited and only allowed to use a 2x scale factor (and some displays do have other scale factors, so some of them were not supported.) A partial solution was to change the default font size, altho