What level of CPU would I be looking at for 4K Plex?

[SILENCEuk]

Assuming 2 clients at a time using the server watching a 4k blu ray rip is the system from the LTT video powerful enough for this? Would I need a beefier CPU or even have to wait for gpu support? I have 1080 I can add when its supported and plan on getting the LTT optiplex as a starting point unless this wont meet my needs.(plus new HDDs)

[bitfiddler]

Plex says: https://support.plex.tv/articles/201774043-what-kind-of-cpu-do-i-need-for-my-server/

If you want very basic minimum suggestions:

• No transcoding: Intel “Atom” 1.2GHz (NAS devices based on ARM processors should also be capable of at least one stream with no transcoding)
• Single 720p transcode: Intel Core i3 3.0 GHz
• Single 1080p transcode: Intel Core i5 3.0GHz
• Single 4K transcode: Intel Core i7 3.2GHz

The Guideline

Very roughly speaking, for a single full-transcode of a video, the following PassMark score requirements are a good guideline for the following average source file:

• 4K HDR (50Mbps, 10-bit HEVC) file: 17000 PassMark score (being transcoded to 10Mbps 1080p)
• 4K SDR (40Mbps, 8-bit HEVC) file: 12000 PassMark score (being transcoded to 10Mbps 1080p)
• 1080p (10Mbps, H.264) file: 2000 PassMark score
• 720p (4Mbps, H.264) file: 1500 PassMark score

The CPU Benchmark website is a good resource to see what sort of PassMark score a particular processor received.  From there the LTT machine is good for about 

Multithread Rating

6034

Single Thread Rating

2263

 

[Vroar]

Core i5-11600K for intel or Ryzen 5 5600X AMD

[SILENCEuk]

Thank you for the info, so I'll need a much more powerful system then than the opiplex to do 4K plex

[Wave]

Are you planning to transcode 4k, if so, then yes a beefier CPU is needs and a GPU may also help more. If you're planning just using direct play with 4k, then you should be fine using a less beefier one.

[SILENCEuk]

1 hour ago, Guardian said:

Are you planning to transcode 4k, if so, then yes a beefier CPU is needs and a GPU may also help more. If you're planning just using direct play with 4k, then you should be fine using a less beefier one.

I'm fully new to this so I'm not 100% on what I want/need. I want to be able to have my ripped collection available to my family on my home network and a second homes network in full 4k HDR when source file is in that format. I just presume transcoding is best for that?

[cory]

If you use hardware acceleration it's always easier but you need a license for Plex then.

[SILENCEuk]

that would be fine just need to know what I'd need and if 4k streaming just wouldn't work at all on free plex and a optiplex

[Wave]

On 12/3/2024 at 2:15 PM, SILENCEuk said:

I'm fully new to this so I'm not 100% on what I want/need. I want to be able to have my ripped collection available to my family on my home network and a second homes network in full 4k HDR when source file is in that format. I just presume transcoding is best for that?

If you're planning to stream 4K movies/tv shows outside of your home network, you're going to have some additional factors to consider:

1. Depending on how big the movie/show is, you need sufficient upload speeds (50Mbps+) to stream smoothly
2. Optional: Graphics Card - Helps with Transcoding (See NVIDIA GPU Matrix - https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new)
3. Optional: Number of concurrent users streaming - Beefier equipment 

What transcoding basically does is that if the device does not support 4K or has limited download speed, the Plex server will be forced to transcode that media file into something that the device can process. For example, if your Plex server  upload speed is limited to 10Mbps upload speed but the movie requires 50Mbps upload speed, the Plex server will have to use the CPU or GPU (better) to transform that media into a lower quality in order to stream that movie. Another example could be that the TV that one of your relatives has does not support 4K. As a result, the Plex server will need to transcode the media into a 1080p or 2K movie in order to stream it to their device. All this will consume a lot of CPU. At that point, it's not worth it to get a beefier CPU and it's better to invest in a better GPU because it can transcode way better and more efficiently than a CPU.

Hence, that's why I asked that question of direct play versus transcoding. In an ideal world, let's say everyone meets the requirements  of upload/download speed, 4K TVs, etc. then no transcoding will need to take place and the Plex Server will direct play the media to the users. If everyone is using direct play, then no need for GPU and at that point you just need to account for how many users will be streaming at the same time.

P.S. Plex also has a setting where you can force users to only do direct play and no transcoding at all which means that any users that does not meet the requirements of watching the video (bandwidth, resolution, etc) will not be able to watch the movie/show or may watch it with a limited experience.