4K Plex Server CPU Recommendation

[Durvelle27]

I don't think plex can scale to all of the cores correctly. It seems ok pushes multiple small transcodes to 2-4 threads, but giving 32 threads one job doesn't work.

I wonder if it’s possible to force the use of multiple threads. I remember seeing a setting that asked how many threads to use when transcoding. I have the lastest version as well.

 

[FordGT90Concept]

You already said that it's using 100% CPU. This is a dual core yeah? It's already multithreaded. I mean, what transcoding software isn't? Multithreaded is the only way to do it in real time.

 

[Durvelle27]

You already said that it's using 100% CPU. This is a dual core yeah? It's already multithreaded. I mean, what transcoding software isn't? Multithreaded is the only way to do it in real time.

Yep dual core

I was more responding to his statement about plex not using over 4 threads

 

[FordGT90Concept]

Yeah, there should be an option to change that somewhere in the config. Emby for sure has an option (defaults to "Max").

 

[cdawall]

Pretty positive anythibg I could set to max is set to max. That doesn't mean it can use everything however.

 

[Kursah]

There is a setting for CPU that I set to "Make my CPU hurt" but that's all I recall for PLEX GUI CPU configs.

 

[Durvelle27]

Yeah, there should be an option to change that somewhere in the config. Emby for sure has an option (defaults to "Max").

I believe there is

Pretty positive anythibg I could set to max is set to max. That doesn't mean it can use everything however.

Very true as it depends on how Plex sees and uses resources

There is a setting for CPU that I set to "Make my CPU hurt" but that's all I recall for PLEX GUI CPU configs.

But does it push over 4 threads

 

[cdawall]

There are my current settings give me a sec I am checking to see how many threads it uses.

So this is suicide just the audio transcode, while it does a conversion on another file zero issues at all

Now this is 4K to 1080P "High quality 20MBps" no background conversion active. Definitely does not load all of the threads that I can tell?

4k to 4k (@49.1MBps) for the same video does seem to load her all the way up though

and here is two 1080P to 720P streams going

 

[Kursah]

But does it push over 4 threads

Don't know, the VM I run it on (that also hosts other services) only is allocated 4 threads.

These are my settings:

I don't stream 4K nor try, I don't have a 4K screen in my home lol. But I have streamed 4-5 1080P without issue. I am a Plex Pass member, bought the lifetime license back in 2015 and have been pretty damn happy with it. Most of its deployment life has been in a virtual 2012R2 environment and I gotta say it has performed excellent for my needs.

Also, not sure why I even have hardware acceleration checked being on a VM lol. But it doesn't seem to be kicking up errors or issues.

I will say I did notice a performance improvement going to make my CPU hurt from default, I didn't really test anything else in between and it can absolutely saturate the provisioned threads when there's a lot going on, but again, I have only allocated 4 threads.

 

[FordGT90Concept]

*snip*

Are all those streams smooth though? The idea of transcoding is to not use 100%, just maintain a higher conversion rate than the client needs (e.g. 30 fps for a 30 fps video). If those conversions aren't smooth then yeah, Plex sucks.

 

[cdawall]

Are all those streams smooth though? The idea of transcoding is to not use 100%, just maintain a higher conversion rate than the client needs (e.g. 30 fps for a 30 fps video). If those conversions aren't smooth then yeah, Plex sucks.

The only one that isn't smooth is the 4k one everything else is fine. I also need to retest that tonight on a hardwired machine and not just to my iPad. Wireless ac is nice, but it has its limits.

 

[Durvelle27]

I found a cheap 8 Core Xeon that hopefully can get the job done. Also looking into FirePro for the GPU

 

[FordGT90Concept]

It has to be Polaris or newer to support HEVC.

 

[Durvelle27]

It has to be Polaris or newer to support HEVC.

Anything that supports UVD 5.0 or Higher

 

[FordGT90Concept]

No, UVD = Universal Video Decoder. It's the VCE (Video Coding Engine) that's important server side. VCE lags behind UVD because accelerating encoding is more difficult than accelerating decoding.

HEVC support started with VCE3, implemented in GCN3 (Tonga, Fiji).

 

[Durvelle27]

No, UVD = Universal Video Decoder. It's the VCE (Video Coding Engine) that's important server side. VCE lags behind UVD because accelerating encoding is more difficult than accelerating decoding.

HEVC support started with VCE3, implemented in GCN3 (Tonga, Fiji).

Ahhhh ok

 

[FordGT90Concept]

I'm trying to figure out what changed in VCE4 (Vega). It might be the addition of VP9 encoding which is kind of important but can't confirm anything yet because references are scarce...

 

[Durvelle27]

I'm trying to figure out what changed in VCE4 (Vega). It might be the addition of VP9 encoding which is kind of important but can't confirm anything yet because references are scarce...

Yes it seems Vega and RX400 series added support for VP9 and 8 & 10 Bit decoding unlike the rest

 

[FordGT90Concept]

My 40 hour transcode was successful. 20 GB h.264 -> 3.5 GB HEVC. Ironically, HEVC doesn't work on my computer because my R9 390 doesn't support it. It works on the Xbox One S though. I'm going to have to keep both files until Microsoft gets their head out of their bum (I hope). I mean, if a SHIELD can handle 4K h.264 then why can't an Xbox One?

 

[Durvelle27]

My 40 hour transcode was successful. 20 GB h.264 -> 3.5 GB HEVC. Ironically, HEVC doesn't work on my computer because my R9 390 doesn't support it. It works on the Xbox One S though. I'm going to have to keep both files until Microsoft gets their head out of their bum (I hope). I mean, if a SHIELD can handle 4K h.264 then why can't an Xbox One?

That’s a long time for 1 file

And yea that’s true. Even more so for the Xbox One X that has a Polaris GPU

So this is what I’m looking at

Xeon 8 Core
16GB RAm
GT 1030