Debug/troubleshoot stutter?

I’ve been experiencing occasional stutter with high bitrate files and I’m not sure how best to troubleshoot this.

For context, I’ve recently revamped my home theater setup, so everything is new and should be performant. The pipeline looks like this:

  • DS918+ NAS
  • 4x WD Red 3 TB drivers in RAID 5
  • Plex Media Server, latest version, running in Docker (no Plex Pass)
  • Cat 6a ethernet cable
  • NetGear R7000P router
  • Wifi (possible weak link)
  • Infuse Pro
  • Apple TV 4K
  • 18 Gbps 4:4:4 HDMI cable
  • LG C8 OLED

After several weeks assembling and configuring everything, I sat down to watch an episode of Planet Earth 2 to test drive my new system. The file is 4K, UHD, HDR 10 and all the other relevant acronyms I could find - I figure if I can play a “max quality” file smoothly, everything else will play smoothly as well.

Unfortunately, I’m seeing what appears to be occasional stutter. It’s possible I’m seeing OLED judder that I’m not used to and parsing it as stream stutter, but I’ve tweaked my picture settings and don’t think this is the case.

What’s the best way to diagnose my pipeline? Ideally there’s a debug option in Infuse, similar to Youtube’s “stats for nerds”, showing metrics like dropped frames and buffer size. The equivalent in Plex would also work. Alas, I haven’t been able to find a debug mode for either app, and I really don’t want to start messing around with low level tools like iostat and Wireshark!

There’s currently no real debug setting in Infuse but with the way that the new WiFi is so sensitive to a multitude of issues I’d say the cheapest and quickest test would be to run a cat 6 cable in place of the WiFi even if it’s temporary at first to see if that makes a difference.

With the latest 4K TVs there are even settings for picture that can cause a stutter so that may be another avenue to explore.

I’ve tried wired instead of wifi, and NFS instead of Plex Media Server. I’m still seeing occasional stuttering and I’d love some advice on how best to troubleshoot, other than low level network analysis on the Linux server side.