If your monitor or an HDMI connection is humming, you should rule out a fault. Here you can read how to recognize faulty ...
HDMI 2.1 is a solid all-rounder with support for 4K at 120Hz, or 8K at 60Hz. HDMI 2.0b is a solid choice for 4K 60Hz, too, ...
The extras they provide are what separates Google TV from Samsung TV, Apple TV, Roku, and all the other services out there.