So I used IntellJ 14 with the vm options -Dis.hidpi=true. According the the following blog post, IntelliJ 15 has native high dpi support for UHD/4k monitors:
So I booted up IntelliJ 15 today and everything is super tiny again. I don't see anything in settings for either "dpi" or "scaling." So the automatic high-dpi obviously isn't working. How do I set it manually? How is IntelliJ supose to auot-detect it? I'm on Gentoo Linux running the i3 window manager.