Just went to render a DNxHD clip to h264 and for whatever reason CUDA / mercury engine is now enabled for transcodes, and it actually works. I have in the past used it but it never seemed so fast or reliable, or built into media encoder by default. Maybe some settings were reset in an update, but transcodes are now literally taking 1/10th the time they used to. Pretty great. Could be it was just updated recently to work with my GTX titan? But this is a major upgrade to my workflow. Even nicer is the CPU remains available for other tasks.