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, although it still did nothing about scaling icons.
We promised a pleasant surprise in each new IntelliJ IDEA 15 EAP, and today we're delivering on that promise with the newly released EAP build, that, a