Beginner sense check, Plex CPU usage in TrueNAS Scale

[chri5]

I recently retired my old PC and turned it into a NAS (TrueNAS-SCALE-22.02.0.1). I know it's not an ideal setup (see signature) but it should be ok for plex and nextcloud.

I had some huge 4k mkv video files that needed converting in plex. My CPU ran at 100% when converting, is this normal? See screenshot.

 

[Kris Moore]

This is normal, plex is going to thrash your CPU when doing transcoding, especially a large 4K video like that. Best way to avoid that is to have some GPU offload setup, which works with Intel chips with the QuickSync feature, or Discrete Nvidia GPUs right now.

 

[buckyball]

You can probably get a couple of more GB of free RAM on your system.

Check your BIOS settings and dial back the amount of RAM allocated to the integrated GPU for the video buffer. I also had a Ryzen 3400G and got back to 15.4 GB.

Please let me know if this helps.

 

[indivision]

Also, make sure your settings in plex (and displays) are right so that it doesn't transcode if it doesn't need to (ie. allow "pass through"). Presumably, you were trying to see the video on a screen that doesn't support 4k?

 

[mervincm]

Also, make sure your settings in plex (and displays) are right so that it doesn't transcode if it doesn't need to (ie. allow "pass through"). Presumably, you were trying to see the video on a screen that doesn't support 4k?

Excellent advice if this happened at view time. Way too much transcoding happens because of poor client settings (low bit rate or "auto") but OP said converting. I may be too literal here these are not the same thing. In plex, items in your conversion queue are being processed by the media optimizer, not an on-the-fly transcode. This is when you tell it ahead of time to re-encode a library to a specific bitrate. https://support.plex.tv/articles/214079318-media-optimizer-overview/

OP if you have a plex-pass you, unfortunately, will not be able to take full advantage unless you run PMS under Windows. Only under Windows can you take advantage of your APU and perform hw-assisted transcoding on an AMD GPU.

 

[indivision]

In plex, items in your conversion queue are being processed by the media optimizer, not an on-the-fly transcode.

Aha! Good call. I assumed convert==transcode here because I didn't realize Plex had this capability.

 

[chri5]

Thanks all, some helpful suggestions here. I've since upgraded the 32gb ram. I am hoping the truecharts AMD plugin will allow me to take advantage of the Vega graphics inside the 3400G to take some load of the CPU but I can't get it working.