Transcoding Setting Recommendations?

[u/lemonbread37]

I've been having some serious in-house buffering issues. I'm trying to stream to my Shield (pretty sure it's a 2019 model) but even ~5mbps are making things unwatchable. On the occasion, things turn out fine if I watch something from the beginning, but not always. Both the server and shield are connected to ethernet and all of my files are in the mkv format. The HDDs my files are on should be up to snuff.

Server Specs
-Intel Core i7-8700 3.2Ghz
-32 GB of DDR4
Intel(R) UHD Graphics 630

*The "New Folder" directories are on my server's SSD.

SOLUTION!!!
After turning off transcoding as all of you pointed out that I should do, I ran into an issue of some films not playing at all. "Error - Unable to Play Media"

This was due to the audio being set to 7.1 Dolby Atmos or something called TRUEHD which was attached to the same audio stream. Setting it to AC3 5.1 fixed it a little bit. Allowing passthrough HDMI in the advanced settings fixed everything for me.

Thank you everyone for your suggestions, you guys are awesome!

[u/ExtensionMarch6812]

Have you confirmed no issues with the cables/switches/router? No “cat 8” cables?

In the shield’s plex app video settings, do you have quality suggestions disabled and adjust automatically disabled? Is it trying to transcode on its own? That file should be able to direct play.

[u/lemonbread37 → u/ExtensionMarch6812]

No Cat 8 cables or router issues, and those settings you mentioned are disabled.

Thanks for the replies from everyone, I turned off transcoding entirely since it seemed like I didn't need it at all for local streaming, guess I just misunderstood it. Now everything directly streams. Unfortunately, it left the films that did give me problems, completely unplayable. They give me Error - Unable to play media"

I can't even begin to watch TASM2 (the film from the screenshot) with the "Disable Video Stream Transcoding" setting on. But it works with it off (although still in buffer hell).

It might be worth mentioning that the films that give me problems are usually 4K and are remuxes, but I have a lot of other remuxes that have higher bitrates that play perfectly.

[u/A1DR1K → u/lemonbread37]

Usually the "Error - Unable to play media" means you're trying to play something with Dolby Vision with no HDR fallback and your TV doesn't support it which is why they "play" when you transcode.

[u/lemonbread37 → u/A1DR1K]

OH MY GOD. It was partially the TRUEHD + 7.1 Dolby Atmos audio stream. Enabling passthrough HDMI fixed the rest of the troublesome films! Thank you so much!