Macbook Pro, late 2016 (Radeon 455 model).
TV: Samsung UN40KU6270 40-in. Smart 4K UHD LED TV
Cables (tried two different 4K @ 60hz certified ones)....
Still says 4K @ 30hz in about this mac>system report > graphics/displays
Help!
Got it working.
Used SwitchResX, to force 60hz!!!
Also followed instructions on another thread to put TV to UDH color mode, Game settings - even though I can now switch that off, and it still is at 60hz!