I’m going on a trip, and I was attempting to queue multiple titles to download to my mobile phone. I have quality set to “Medium.” The new Plex app appears to monitor the transcode progress, but the server is only processing one file at a time. I have the max simultaneous transcode streams set to 4 concurrent. My PMS is a Mac Mini M1 (2020) with 16 GB of RAM. I’m looking at Activity Monitor and the CPU% for Plex is around 70-80%. The CPU activity graph does not look busy, and it appears Plex is only using the Efficiency cores, not the Performance cores.
If I were to play a title and have it transcoded live, Plex would use multiple CPU/GPU cores. If multiple users / devices watched content, the CPU usage rises accordingly.
Why is optimization / conversion for download running as a single-threaded job?
Server Version#: 1.41.8.9834
Player Version#: 2025.20.0 (1153)
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>
I updated the server to the new version, but now I have some new issues:
The webpage “Conversions” is flickering and refreshing a lot. At first, I can see the progress of transcodes, but they quickly disappear and are replaced with “Waiting…” Meanwhile, the iOS app does show meaningful progress.
The transcodes don’t appear to be going very fast. The CPU usage is not as high as I expected. Even with 4 jobs running simultaneously, there is plenty of headroom, and the transcode rates appear to be slower than a single job. It’s like they’re all sharing 1-2 cores (200% max).
Intermittently, if I’m on the Conversions page and click something else in the sidebar, the entire web page locks up hard and stops responding. The only way to fix this is to close the Plex tab, and relaunch it from the Plex “Preferences…” menu item.
I’m using Safari, and definitely logged in / authorized. I’m the administrator. There’s no way I would be able to see the Settings without being authorized.
