Late 2015 21.5" iMac Stuttering on 4k Life of Pi

[Snurry]

I'm using vlc player to watch Life of Pi in 4k but it keeps stuttering and getting image errors.
Is this a limitation of the machine or is there something I can do about it.
CPU usage is maxed out.

 

[Kcetech1]

can try using a different player software package like 5Kplayer for Mac, but it seems to be more of a system/GPU issue. I can make my 2015 playback smooth with bootcamp and either VLC, 5K or best of all Plex or Kodi.

 

[cynics]

How was the video encoded? Sounds like its too complex for your system to decode in real time.