[Bibio]

@Warner306 I was wondering would their be any point in sending my RX560 4GB back and replace it for a RX580 4GB? I mean what benefit will I get? Will the 580 be much better in performance or is it pretty much an overkill for what I use it for (movie playback only).

 personally i would get things playing smooth without glitches with the card you have then spend the money on getting an ISF calibration done to the system. after that then there would be no more fiddling.

another thing you might want to consider is upgrading your motherboard.   

 That is solid advice thank you.. If I upgrade my motherboard I would need a new cpu and ram aswell.. lets see thanks anyway Do you reccomend a motherboard and a cpu that will be sufficient? I can go atx as I am thinking of changing my case to silverstone gd09b thanks

Also what benefit will I gain from upgrading my motherboard as I only with movies with this HTPC? Thanks 

 a new MB will give you faster bus speeds, newer chipsets and if the correct one is obtained a nice M.2 pcie HDD for your OS/programs.
depending on your MB choice then you can keep your CPU and memory.
i would not be spending a wad of cash on a mid/high end card if the MB GPU socket was older spec, thats like sticking a sports car engine in a family saloon. yes it will work but the brakes and suspension aren't up to the task.
as computing components advance so do OS and programs to take advantage of it.

having said the above, if things are running fine and dandy then keep what you have till you really need to upgrade.
its true what others have said, the returns v's outlay in PQ have diminishing returns. ok so you might be able to run madvr almost flat out with a high end system. but in reality your not going to notice that much difference in PQ with using 1080p and 4k content.
all you are trying to do is better the PQ of "hardware players" and add ease of playback.