This might a blondish question, but I'll shoot anyway 
My LE installation (8.2.5) sits on pretty "oldish" DELL E6420 Laptop (with Intel HD Graphics 3000) and I *assume* it carries HDMI 1.4 (could not yet validate the HDMI version). The DELL is currently plugged into my AV receiver (non 4K supported YET - will be upgraded).
If I'd wanna view Ultra HD (4K) content, do I need to upgrade my DELL "htpc" as well OR is it enough just to upgrade my AV receiver?
//timo