Apple has released a major update for Final Cut Pro X



From MacRumors:

The program now supports optimized playback and rendering utilizing the dual AMD FirePro graphics chips found in the new Mac Pro, along with support for video monitoring at resolutions up to 4K via Thunderbolt 2 and HDMI on select Mac computers. The update also includes 4K-optimized content, and a host of other additions and performance enhancements.

  Apple Updates Final Cut Pro X with 2013 Mac Pro Compatibility, 4K Content