Thanks for the quick response
Yes, I am running Windows 10 on both PC's at the moment, and will continue to do so.
With regards to Netflix, I have the Netflix app on my Panasonic TX-58EX700B 4k TV and the Panasonic 4k HDR Player DP-UB420, so I don't really need to run it on my HTPC, although I have tried out the unofficial Netflix add-on... which works very well btw. All my .mkv's are on my NAS, so I can watch them anywhere in the house, or out and about, but the 4k HDR content I will only want to watch at home.
Over the years I have ripped my entire DVD and Blu-Ray collection to .mkv, but would like to do the same with the 4k and 4k HDR titles I have (and will) purchased going forward. I know I could not bother and just use the discs in the player, but I want to upgrade the Bedroom TV to 4k during this years Black Friday deals, and don't want to buy another 4k HDR player... nor keep going downstairs to get the discs as I am disabled
Another thing to note is that both the TV and HDR player are full DLNA compliant, and even appear as renders in Kodi using the 'play to' function.
What also surprises me is what little hardware Kodi needs to run on in order to playback 1080p .mkv x264 and x265, as you said "do the math", and yet my HTPC cannot playback 4k HDR as it buffers and doesn't auto switch to HDR mode, as is the same for my main PC, which will playback 4k HDR, but again doesn't switch to HDR mode. Obviously not auto switching to HDR mode is due to the fact that neither motherboard has HDMI 2.x, only 1.4x.
I think my best bet is to 'suck it and see' and purchase a GTX 1030 fanless, install it in the HTPC and see what happens, and then try it my main PC.
I'll let everyone know how I get on by reporting back here with the results, as it may help others