Unable to Stop PMS from Using 100% CPU Windows 10

Plex Media Server
1

Server Version#: 1.19.1.2645
Player Version#: 4.22.3

I am a 3 year Plex user with Plex Pass. PMS was loaded on a windows 7 Pro PC with G2020T - 2.5 GHZ CPU and 4 GB Ram.

I use 2 HDHomeRun Connect Duo tuners to record OTA content. I also have MP4 movies. I am using the HDHomerun DVR to record the OTA tv shows because Plex DVR recordings always had issues (freezing, pixelation).

I noticed the CPU was very loud during playback on the Plex apps and thought it was due to the age of my PC. I purchased another PC and installed a fresh PMS on it this week.

PMS is now installed on a Windows 10 Pro PC with a i5-6500 3.2 GHZ CPU and 16GB RAM.

Plex apps: Amazon FireTV, Samsung TV, Roku, Apple TV.
On all apps and the web app, Plex is still using 100% CPU during playback to transcode. If I play my recordings back on the HDHomerun app, it uses less than 20% CPU.

Internet: Web app and Samsung tv app connect via Internet. Amazon Fire TV, Apple TV and Roku app connect via Wifi and are close to the router. All have good connection strength.

I tested playback using recordings recorded using the Plex DVR feature yesterday. Recorded 3 recordings. These also used 100% CPU during playback.

What am I doing wrong? Is there anything I can do to optimize the drain on the CPU? I already added 30% more processor speed and 300% more memory strictly for the PMS. I searched and ready forums and don’t see anything wrong with my setup.

Plex Media Server Logs_2020-04-09_18-24-38.zip (3.8 MB)

2

Transcoding video is CPU intensive. It is expected that the CPU will be at 100% when this happens. It does not matter if you’ve a Celeron or an i9.

Do you have hardware acceleration enabled? If not, do so. It will offload transcoding of MPEG2 and H.264 to the embedded GPU in the i5, reducing the load on your CPU…

If you’ve a video card installed, what make/model? It may impact your ability to use hardware acceleration.

There are times where the Plex transcoder gets ahead of the stream. When this happens the CPU (or GPU) utilization will drop and it will show as “throttled” in the Plex Dashboard. In this case, throttled is a good thing.

https://support.plex.tv/articles/203064726-if-a-transcode-is-throttled-is-that-bad/

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Edit: Check b/w settings on Samsung TV as well, since it is remote.

When using Safari:

MDE: Cannot direct stream video stream due to profile or setting limitations
MDE: Cannot direct stream audio stream due to codec ac3 when profile only allows aac

Check server and client settings for any bandwidth limitations (since Safari user is remote). If the stream exceeds any bandwidth settings, then it forces Plex to transcode the stream.

On Plex Media Server: Server Settings -> Remote Access

For Safari user: This must be done by the Safari user.
Login to Plex Web. Settings -> Plex Web -> Quality.

Also, consider using Plex for Mac. It is more full featured than Plex Web, and will direct play many more audio & video formats (b/w limits still apply).

Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: Selected protocol dash; container: mp4
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: analyzing media item 6091
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: Direct Play is disabled
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: media must be transcoded in order to use the dash protocol
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: no direct play video profile exists for http/mpegts/mpeg2video
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: no direct play video profile exists for http/mpegts/mpeg2video/ac3
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: no direct play video profile exists for http/mpegts/mpeg2video/ac3
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: E153 - Episode 153: no remuxable profile found, so video stream will be transcoded
Apr 09, 2020 18:23:04.610 [1832] DEBUG - MDE: Cannot direct stream video stream due to profile or setting limitations
Apr 09, 2020 18:23:04.610 [1832] DEBUG - Scaled up video bitrate to 15930Kbps based on 1.500000x fudge factor.
Apr 09, 2020 18:23:04.610 [1832] DEBUG - Codecs: testing aac_mf (encoder)
Apr 09, 2020 18:23:04.611 [1832] INFO - [FFMPEG] - MFT name: 'Microsoft AAC Audio Encoder MFT'
Apr 09, 2020 18:23:04.612 [1832] DEBUG - MDE: Cannot direct stream audio stream due to codec ac3 when profile only allows aac
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For the remainder of your devices, check the Plex Dashboard’s Now Playing section during playback to see if the video or audio is transcoding.

There is too much interleaved playback in the log files for me to track which device is playing which video.

5

Thank you for the feedback and suggestions. It is most appreciated.

6

Hardware acceleration did the trick!

Right now I am running 5 streams of 1080p recordings to test. The CPU usage has remained under 51% and memory usage is under 28%.

  • Samsung TV (ethernet) - Video and audio both direct play.
  • Roku TV (wireless) - Video transcoded. Audio direct stream.
  • Amazon Fire TV (wireless) - Video and audio both direct play.
  • Plex Web Chrome on Windows - Video and audio both transcoded.
  • Plex Web Safari on Mac - Video and audio both transcoded.

Thanks for the assist! Super thrilled my computer no longer sounds like a rocket ship about to blast off.

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