Plex Server: 4.79.4 (via linuxserver/plex Docker image, on a Mac Mini M1 running MacOS 12.3.1).
Plex iOS: 8.1.1 (iPhone Mini 12 running iOS 15.4.1)
The download feature doesn’t seem to be doing so well for me here.
Running Plex Media Server on docker on via the Linuxserver image, I’m trying to transfer ~900 songs to my phone and it’s going really slowly. Approximately 15-20 seconds per song so far. They’re all 320kbps mp3 files, so approximately 10-15MB per file. I have a 2000Mbps down/800Mbps up fibre connection at home, my server is plugged into a 2.5Gbps ethernet port on my router, and my phone is 2 meters away (iPhone 12 Mini). I did a speedtest to confirm my internet connnection isn’t the issue:
Now on my phone, I set all the download settings to “original”:
On the server, as you can see on the bandwidth graph, it does seem to properly detect that my phone is on the local network:
But those peaks and valleys seem odd to me, like the connection keeps cutting off and restarting. The activity spinner in the top right will also spin to show activity for about 1 second, then the animation stops for half a second like the server isn’t doing anything anymore, and then get back to spinning for a second, and so on:
I’m pretty sure the server doesn’t mistakenly try to transcode, as the processor and RAM graphs seems pretty unbothered by all this:
But that could just be because Plex is running inside Docker? This is all running on a Mac Mini M1 (through the ARM64 docker image). The actual MacOS activity monitor does show slightly increased CPU activity but it’s just ~15% (as opposed to ~5% when idle).
This is the docker-compose file for my Plex setup, including info about port forwarding, maybe I’m missing something here?
I briefly considered it could be an issue caused by Docker running on MacOS, which is infamous for poor file I/O performance but:
- A recent Docker release (4.6) did a lot to mitigate this via virtiofs. It’s still going to be slower than running it on Linux but it’s definitely not that bad anymore.
- With the exact same setup, I’m perfectly able to stream a 4K movie which is over 60Mbps from Plex to my phone without any buffering, so the issue doesn’t lie there.
Checking the logs, I’m not seeing any type or error or warning, however, it seems like each file gets downloaded a bunch of times in a row. You can see here, the same file getting requested and downloaded twice:
