Long story short, I'd like to output a native 4K signal from the HDMI output of my rMBP to my 4K home theater projector. In Windows on Boot Camp, it works fine. I can watch native 4K video content very easily. There are a few graphical hiccups here and there which I attribute to the drivers, but I can get it up and running without issue. However, in Mac OSX, I can't seem to get any resolution above the native resolution of the rMBP screen, even if I'm using the projector as the primary and only display. Does anyone know a way around this?