
Just released earlier tonight, Apple's OS X Mavericks 10.9.3 beta appears to have built-in support that enables all compatible 4K displays to be set at a "Retina" resolution, with an option for 60Hz output. The compatibility was first discovered by Twitter user @KhaosT, and was tested with both the Late 2013 Retina MacBook Pro and redesigned Mac Pro in conjunction with Dell's UltraSharp 24 Ultra HD Monitor.

Native support for 4K displays could also indicate that Apple is gearing up to release a higher-resolution Thunderbolt Display, as Apple last refreshed the monitor over two years ago. A number of other companies also introduced more affordable 4K displays at CES 2014 in January, with options from the likes of Lenovo, Asus, Seiki, and LG expected to hit the market throughout this year.
Article Link: OS X Mavericks 10.9.3 Beta Contains Native 'Retina' Resolution Option for 4K Displays