Transcoding a single file put CPU at 100%

Plex Media Server
1

Server Version#: Version 1.41.5.9522
Player Version#: various IOS versions all up to date

My hardware :

  • CPU : Intel(R) Xeon(R) CPU E3-1231 v3 @ 3.40GHz
  • 32Go of RAM
  • 2x2To HDD

I also installed ffmpeg.

Hello all,

I recently made a fresh install of my linux server (Debian 12) hosting my plex media server. On the previous install, everything worked fine. I was able to have 4 simultaneous transcode sessions without any issue or lag.

Now, after having reinstalled all the system including PMS, when only trying to play a single file using transcode, my CPU usage is stuck at 100% and the bandwith usage is put at its maximum.
And in addition, the video is lagging with a stop every 2sec.

image
image785×637 55.1 KB

and the info is the following, it is a simple h264 file in 1080p that worked perfectly fine before.

image
image314×441 32.1 KB

The hardware of my server stayed the same excepted the replacement of a HDD (similar)

My transcoder settings are the following :

  • quality : high speed prefered
  • buffer size : 30s
  • H264 presets : super fast
  • HDR tone : activated
  • hardware acceleration : true
  • encoding via hardware : true

In the distant access section I did not set any limitation for the bandwith, and for the limitation of the distant flux I tried both original and a limitation at 8Mbit/s (1080p).

I also tried a htop before and during a play event (before, CPU usage is aroung 3%)
As you can see below, it is taking all ressources…

image
image1287×576 62.5 KB

I’m honestly lost, so if any one have some clue to solve this issue I would be pleased to read it.

2

Your CPU does not have HW acceleration support

Do you have an external Nvidia GPU which isn’t being seen / selected ?

(Settings - server - Transcoding - SHOW ADVANCED)

3

Hello,

thanks for the reply, looking back at the option I put the following

image
image507×450 23.5 KB

Knowking that I let the option on Auto.

The very strange thing, is that I had a serious improvment after renaming the server. After the install, I renamed it the same way as the old one. After simply putting a 2 in the name to change it, consumtion dropped down…

However things are better, there is still a high load on the CPU with a simple h264 1080p transcode…

4

Gemini Lake CPUs are fickle

I’ve had to manually select the UHD 600 GPU for it to work right

5

My bad I picked the second server I have (on Synology NAS).
For the Debian server on Intel XEON

image
image552×352 20.6 KB

so does it mean that I have to uncheck the hardware acceleration option?

6

Hello

I’m still struggling with the processor consumption of my server since my fresh install.
A single transcode from a 1024p h264 source eat 80% of the processor… we are really far away from the previous behavior… showing approx 15 to 20% max

If you have any clue on a possible issue…

Thanks beforehand

7

Which Xeon Syno do you have ?

I ask because there are some Syno systems now which support external Nvidia GPU.

One thing we’re hoping for is better CPU support with FFMPEG 6.1