Hi
I've read that many has/had)(?) problems with playing mkv-files, stuttering/pausing for awhile etc.
But couple of days non intensive searching, I haven't really found a solution for that issue. Except buying a better hardware. 
(I've also a DN2820FYK, but it is even worse than that PYH)
So mp4 files plays without any issues, but mkv doesn't.
I read somewhere that ffmped addon should fix the issue and I downloaded it, but how to do enable it or do I need to?
Any other suggestions/help?
It really isn't serious problem, I've a I5-4570 with 32Gb of ram SFF which can play mkv-files without a problem.