4K 60Hz possible on Mountain Lion with AMD 7850?

[Haru-tan]

Greetings.

I have a perfectly functional installation of Mountain Lion, however I am having difficulty in getting it to output 4K at 60Hz via DisplayPort 1.2 with my AMD Radeon Hd 7850. 4K at 30Hz works perfectly but as soon as I switch the monitor to DisplayPort 1.2 mode and reboot for 60Hz, I am presented with a black screen immediately following the Apple boot screen.

Does Mountain Lion have a pixel clock limit or something similar which is preventing me from doing this and if so, are there any workarounds?

I am aware that I could simply install Mavericks (which has full support for 4K at 60Hz) but I much prefer the stability and well optimised GUI performance of Mountain Lion.

Thank you.

 

[Haru-tan]

Bump. Anybody?

I have yet to find a solution to this conundrum but perhaps an NVIDIA GPU would work? I would expect the NVIDIA Web Driver to be more comprehensive than Apple's in terms of resolution support.