CPU Usage/ Transcoding

Plex Media Server Desktops & Laptops
1

Server Version#: 4.22.2
Player Version#:

Hi all.

Before posting this message, I did a Search on the forum and looked up things like “CPU Usage”, etc. Yes, there was quite a few results, and I perused through them. But I don’t know if each situation is unique, so, here we go…

I have Plex Media Server, version 4.22.2, installed on my desktop PC; my specs:

  • Windows 10 Pro, Version 1909, OS Build 18363.720; 64-bit
  • Aorus Gaming 8 Motherboard
  • Intel (Quad) Core i7, 7700K, 4.20GHz per core
  • 32GB RAM
  • EVGA nVidia GTX GeForce 1080 GPU
  • Corsair 1050 watt PSU
  • DSL High Speed Internet connection (80Mbps+ down speed; 10Mbps+ up speed)

At our TV set in our living room, we have a Roku Ultra player with the Plex app on it. On the desktop computer I described above, I’ll have digital video files that we’ll stream through the Roku player to be displayed/ played on the TV.

If I happen to be sitting at the computer doing “whatever” and my wife happens to start streaming a video from the computer through the Plex app on the Roku player, I’ll hear the CPU fan speed up at a high rev. I’ll then launch the Task Manager, and, the Plex Transcoder CPU Usage is up between 90 and 100%

Now, this 90 to 100% CPU Usage doesn’t last long (a minute or so); it will then drop back down and my system’s “normal” idling CPU Usage will hover between 10 and 15%.

So: Is this “normal” when the Plex Transcoder first starts? 90 to 100% CPU Usage?

The digital video files being streamed from the desktop computer to the Roku Ultra Player/ Plex app are usually either .mkv or .mp4 files, 1080p (not 4K).

Is there some setting I can tweak or adjust in the Plex Media Server to alleviate CPU Usage and shift it somewhere else?

Or, as I asked, is this “normal” when it is first starting to transcode a video from PC to the Roku Player/ Plex app?

My fear is, say I launched a video game on my computer - one that will have a high demand on CPU, RAM, and graphics - and then also a video starts to get streamed and transcoded through the Roku/ Plex app? It might overtax my system and I’ll have a system shutdown (a safety feature if the CPU is maxed out to prevent overheating).

I’d appreciate and helpful tips or info.
Thanks,
Pez

2

Yes. The server needs to fill the playback buffer of the client with pre-transcoded chunks of video. Afterwards it switches to ‘throttled’ mode, if it can transcode faster than the chunks are needed.
https://support.plex.tv/articles/203064726-if-a-transcode-is-throttled-is-that-bad/

If you subscribe to Plex Pass, hardware transcoding will be unlocked, which enables Plex to use the QuickSync unit in your CPU to perform the transcoding. This can reduce regular CPU load immensely.

A well-built system must be able to handle 100% CPU load, even for prolonged periods of time. If it cannot do that, it is not well built or simply un-suitable for the use case as Plex server.

3

It does sound quite normal to me as the CPU ramps up until the buffer is filled. This would particularly happen in the event of transcoding.

But there is another issue. In general servers Plex or other should have no other regular duties. Doing things on your server while it is trying to serve is a good way to introduce problems. Plex has tried their best to work and play well with other programs but servers have a lot of work to do.

One thing that might help is to be sure that hardware acceleration is on and working.

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Hi! Thanks for the replies!!!

OttoKerner: So, the CPU reaction (usage up to 90/ 100%, plus the fans revving up) is normal, eh? After those pre-transcoded chunks of video, it switches to a “throttled” mode, huh? Yeah…I’ve noticed (like I mentioned in my original post) that it doesn’t last long - about a minute - and then the CPU & fan go back down to normal.

But no, I don’t subscribe to Plex Pass, so I guess I would not be able to take advantage of this hardware being unlocked (QuickSync…reducing CPU load). The only thing I really use Plex for is the streaming of digital video files from my PC to the Roku Ultra device. Roku has its own built-in app for this that’s available for free; I had tried it, but it couldn’t handle (decode?) certain audio codecs embedded within certain video files. Plex can decode it, so… :grin:

And you also mentioned that “A well-built system must be able to handle 100% CPU load, even for prolonged periods of time. If it cannot do that, it is not well built or simply un-suitable for the use case as Plex server”.

I can say with confidence that I do in-fact have a well-built system. Besides have some good, quality hardware components comprising my system, I keep my overall system (the OS, etc.) very clean. No junk or unnecessary programs/ background processes hogging system resources. Only the minimal, most necessary programs are installed on my “C” drive. I have a separate hard drive installed in my tower unit for storage of other files, etc. And, my OS (on the “C” drive) is on a Solid State Drive; zippy fast!! :stuck_out_tongue_closed_eyes:

But, I have to admit, I was not aware of that particular item you mentioned of “A well-built system must be able to handle 100% CPU load, even for prolonged periods of time…”. I guess I just get a little wary & leery when I see my CPU’s usage go up to 90/ 100% and the fan is revving to cool it down.

I shouldn’t be too worried, though: The fan cooling my CPU is technically blowing onto a mini radiator, for my system is liquid cooled for my CPU. Plus, my tower case is a CoolerMaster and has lots of system case fans blowing, too :joy:

But…I’ll share this: There was this one time I was playing a game that was very demanding of system resources (I think it may have been “Shadow of the Tomb Raider” with graphics settings maxed out). During game play, I either Alt-Tab’ed or Ctrl-Alt-Deleted, and then I minimized the game to the Taskbar (it was still running, just minimized). I then went to YouTube to look up a video walkthrough of the game to help me past a spot I was stuck in. While watching the YouTube video (and the game still running in the background but minimized to my Taskbar), I heard my system fans speed up…and then my system “blinks” and shuts down and then goes right into a reboot. Everything was fine when it got back to the Windows login screen/ desktop, but I think I may have overtaxed things to cause that shutdown/ reboot :wink:

Elijah_Baley: So you concur with OttoKerner; CPU ramping up during initial transcoding is normal, eh?

But that item you mentioned about “One thing that might help is to be sure that hardware acceleration is on and working”: By “hardware acceleration”, are you referring to the same thing that OttoKerner was? Plex Pass and hardware transcoding being unlocked? Or are you referring to something else, like something within a Windows 10 setting?

Pez

5

That’s how the transcoder works:
It uses every available horse in a wild gallop until it gets far enough out in front to slow down and have a carrot. At my house when Plex has my CPU up against the wall frisking it for contraband - my blowers run.

When I hear that I know something has gone terribly wrong - 'cause all my stuff is supposed to Direct Play…lol

Hardware - anything - AFAIK - will require a Plex Pass.

As far as the transcoder and CPU/GPU usage - I wouldn’t want it working any other way. If you’re going to allow the transcoder to do it’s job it has to use as many resources as it can to gain that lead - or streaming simply sucks. Nobody wants that.

6

Yep hardware acceleration is the name that Plex calls it in their settings.

You are reall making a mistake by gaming on the same system that you are running Plex on. Servers should serve and very very little else.

Plex, when transcoding, is system intensive and gaming is system intensive. Combine the two and you get your system over stressed in many cases.

I am frankly surprised by every poster that says they are running Plex on a system they are gaming on and report they are having little problem particularly if they are running Windows as an operating system. That is at least unless the system they are using is one of the extreme beasts that some people use. I found it is cheaper to buy a decent gaming system and av average system for Plex than it is to buy one of those “beast” systems.

7

My server is on my Gaming Rig.

Gaming and Transcoding is a lose-lose thing, but for me it’s a non-issue.
All my material Direct Plays.
I ‘create’ it ALL.

If one expects their Gaming Rig to Game and Transcode.
It’s gonna take more than a Gaming Rig.

Transcoding requires every available resource to get the transcode out in front of the Playback, then it bursts at 100% to keep the buffers full. If a Burst occurs when you walk into a room full of flesh eating beasts - you’re gonna die and the viewing experience on the streaming end will suffer as well.

I can deliver up to (tested) 4 Direct Play Streams while gaming and no one notices a thing.

I do know my limitations and make sure they don’t limit out.

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