Depending on the encoding, 4k might not be all that great on an I3, depending on the model, on my old I7 4970k some of the 4k videos ate up a lot of CPU time to decode. 4k netflix, you should be all right with the I3, 4K BluRays... Not sure, I don't have any 4k BluRays yet... If you just want to display at 4k, the I3 may be fine, but you'll be limited, for 60Hz over HDMI you'll need HDMI 2.0 and that's on 900/1000 nVidia cards and 400 AMD cards. Over a monitor, you should be fine with displayport on most newer cards.