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, among other enhancements, comes with the complete HiDPI support for Windows and Linux, with fractional scaling of both fonts and icons according to your system DPI settings. It means that you don’t have to tweak the idea.vmoptions file anymore, just use your favorite font (make sure to restore the defaults if you changed them), and enjoy the high resolution IDE completely.
Enough reading already, go ahead and download the latest IntelliJ IDEA 15 EAP, and try it all for yourself.