I recently retired my old television to the bedroom, which I seldom use & dropped a 55"/4K in my circus room.
My Sandy Bridge i7, notebook's 15" display stopped working so I connected it to the new 3840 X 2160 television. I made a copy of my DSLR photo backup on an extra external drive in a USB dock & let Lightroom go crazy for many hours. With a direct HDMI cable the computer runs a bit warm, but supports the native resolution.
My oh my….."What a delight." From 6 to 24 megapixel raw files over the last 9 years, it's wonderful to scroll back & look at full screen. I can even magnify to 100% & get more detail on higher MP shots. There are also many, many jpg's dating back into the late 1990's
The only thing that is a bit confounding; I have a couple Canon Powershots (G12 & G1X,) & the results are quite impressive too.
(Whoops, I mentioned the "C" word.)