CPU cranks to 300-600% and overheats when subtitles are turned on

[ChuckPa]

OK gang,
with what we have gathered here, and over here:

Plex Media Server process uses 100% cpu

I have had a direct chat with the engineer.

What would be nice:

1. XML of the file which demonstrates the problem reliably when playing to Plex/web.
2. DEBUG logs only, VERBOSE logging off.
3. Start Playback.
4. Skip forward (if subs don’t start for a while) until where it subtitles are visible on the display.
5. Now let it play for 60 seconds
6. Stop Playback
7. Wait 30 seconds.
8. Download the logs (Settings - Server - Troubleshooting - Download Logs)
9. Attach the XML and ZIP file here

[Ashus]

@ChuckPa Thanks for the update.

Atm I’m using windows 10 64bit OS, I’ll also include my infos here.

I’ve already posted it in my own thread over here:

Plex Media Server.exe eating up my CPU

Sure, here’s the log, I just performed a quick test on it. Plex Media Server Logs_2019-07-15_13-41-44.zip (3.1 MB) All timings are in GMT+3 (UTC+3). These timings are approximate. 13:36pm: Movie started playing on app.plex.tv, the subtitle was chosen (English external SRT), however the subtitle did not appear (no subtitle shown when movie was playing, but dashboard shows the subtitle, and SRT was getting converted to ASS), hence the PMS CPU here was in low 1% to 0.5% 13:38pm 1x rewind 18%…

And also my Plex Web App logs here:

Plex Media Server.exe eating up my CPU

@anon18523487 how can I get logs from plex web app? EDIT: Nevermind found it! enabled debug and copy/pasted the logs PlexWebLogs.txt (67.4 KB) my time is on GMT+3, however i’m assuming the logs here are showing on GMT+0 timezone. if that’s the case then: Same movie used that started at around 23hrs 50mins 30seconds (approx.) did a 2x rewind, and CPU started to rise (same as above results) left the movie to play with memory leak shown for about 1min.

[ChuckPa]

Please supply the log files which were created by having recreated using the process I describe.

Please post the logs here; not links throughout the forum.

[Ashus]

@ChuckPa

Please supply the log files which were created by having recreated using the process I describe.

Please post the logs here; not links throughout the forum.

Plex Logs:
Plex Media Server Logs_2019-07-15_13-41-44.zip (3.1 MB)

XML:

PlexMedia - Pastebin.com

OS: Windows 10 Pro edition 64bit OS
Web Client: Version 3.104.2 (using Google Chrome)
PMS: Version 1.16.3.1402

Steps taken exactly as instructed (that was the exact same logs used when tested for leaks).

[ChuckPa]

@ashus

Which file in those logs is the one you were capturing for us?

Also, is it possible to wait until all media has been added ?
I’m trying to get a nice clean set of logs for the team.
I look at yours and am not sure which is which. I see multiple playback sessions/attempts.

[Ashus]

@ChuckPa on the timings of those logs I started the movie (Hellboy 2019) on approximately 13:36.

at 13:38 the subtitle (English SRT External) appeared alongside high CPU usage.

Movie terminated at around 13:41.

There was no one except me using Plex, and its on the same user account, I dunno why plex logs shows refreshing other users.

Also no media was added/deleted. Maybe its because I have “Scan my library periodically” ?

I can do another test if needed. I shouldve turned off library scan.

EDIT: To answer your question on which file on those logs, im only looking at the Plex Server log files (the latest one).

[ChuckPa]

It might have well been the periodic scan.
My library is set to scan automatically.

[Ashus]

I think it was.

Does the log show anything useful?

[ChuckPa]

I have not had time to go through them yet in detail. I will have time this weekend.

[dixonbg]

@ChuckPa

This thread has two major issues which needs to be spit.

Hi Chuck, I just realized that you are replying to me… I’m the only one here with G5600. There is nothing to split. These guys do have a real issue.

I just wanted to explain that Tim uses UNRAID, which is a great headless Debian based OS. However, I do noticed this SRT-ASS issue affects also G5600, but in a different way. In his screenshot ALL cores are showing over 90% load. In my case, such videos without SRT subs and with audio transcode load between 1% (throttled) and 30% on all cores. But with SRT subtitles, 1 logical core is at 100% all the time, even when transcoding is throttled. A second such stream loads another logical core at 100%.
Thankfully, I do not have many browser clients, so I don’t care much.

[ChuckPa]

For my sanity sake (which is questionable some days ), the issue is SRT->ASS conversion , regardless of how it is utilized?

I hope so because this is what we are seeing in code. If there is something else, this will result in being a multi-step resolution process.

[Mothy_Tim]

Hi, yes the issue is SRT->ASS conversion, it only takes 1 transcode to max out the system! I have seen 6 transcodes running and the CPU is only at 15-20% so is powerful enough to cope with my needs.

Yes, Unraid is a great headless OS, I have only recently changed to it. Before I was running Ubuntu with Plex directly installed (ie. not in Docker) and had the same problem then, so it doesn’t seem specific to one OS.

I have been away working and so missed that you wanted logs and XML files! Do you still need them? If so where do I find the XML file you’re after?

Cheers,
Tim

[Mothy_Tim]

So last night had another occurrence of my cpu maxed out when transcoding srt to ass for the Xbox client! Changed the subtitles setting in Xbox from auto to always burn and then it was fine, cpu not even peaking at 10%! So will leave it like this until Plex fix the bug!

[dixonbg]

The new beta appears to have fixed the subtitles issue for me. Before that, even paused clients with ASS subs used 100% cpu.

Thank you for the rapid support!

[lordchristiano]

Having the same issue with Qnap ts-563 for several months. Plex mkv with no subtitles uses about 10% cpu, with subtitles 99%…When used via lgtv client or Nvidia shield Plex client. Latest beta doesn’t fix for me.

[jishi]

Heh, “rapid” is not what I would call this, since it was introduced in 1.15.x in February, and started to get reported in April.

But I’m glad it got fixed, finally.

[nibbles]

So you have exactly the same issue as described above?

CPU cranks to 300-600% and overheats when subtitles are turned on

Using Plex Web App (chrome or firefox) choose SRT external subtitle. The plex web app cannot direct play with AC3 5.1 or DTS 5.1 (ironically it can direct play AAC 5.1) instead it will be direct streamed with audio converting AC3/DTS 5.1 to a stereo (aac). Once that happens. the Plex Web App will convert SRT external subtitle to ASS format. With that, the leak will occur where it tries to render the subtitle (showing subs on the media) and gets stuck in an infinite loop. if using aac stereo…

I don’t think that’s true, and the fact that the beta doesn’t address your issue implies that a new topic is warranted.

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