CPU for 4k transcode

[Shamanix]

Hello. I'm gonna build a new PC for TrueNAS running, file ftp, plex, adguard etc server. Was wondering which CPU is recommended for Plex server (hw transcode). Was thinking about Ryzen 3 3200g, but Intel is maybe better for Plex?

 

[joeschmuck]

Welcome to the Forums.

There are a lot of threads here in the forum discussing the various CPUs and performance for 4K transcoding as well as on the Plex forums. Do some research and you will be shocked at how much CPU you will need to buy to transcode 4K, it might change your mind.

 

[Shamanix]

Welcome to the Forums.

There are a lot of threads here in the forum discussing the various CPUs and performance for 4K transcoding as well as on the Plex forums. Do some research and you will be shocked at how much CPU you will need to buy to transcode 4K, it might change your mind.

Hmm. What if i won't transcode? Would AMD Ryzen or an Intel be best?

 

[joeschmuck]

Hmm. What if i won't transcode? Would AMD Ryzen or an Intel be best?

Best is subjective. Both will work fine. Examine the forums and you will find that "most" people are using Intel based but mainly due to personal preference or motherboard features (IPMI for example), but there are others who like the AMD lineup. Have you looked at the Hardware Recommendation Guide in the "Resources" tab at the top of the forum page? There is a lot of great information there which is backed by years of experience. My personal preference is Intel and I have run an AMD system for FreeNAS many years ago but switched to Intel for the motherboard features.

 

[G8One2]

According to PLEX..................

"CPU Requirements

The most basic thing to remember is that the more Plex apps you have playing content at the same time, the more CPU power you’ll need. Generally speaking, if you have two Plex apps requiring transcoded content at the same time, that will require about twice the CPU processing power compared to if there was only one app playing content.


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

If you’ll need to support more than one simultaneous transcode, you’ll need a more powerful processor.


Related Page: NAS Devices

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. "

 

[spiceygas]

As an anecdotal datapoint, I have 2x Xeon 2680v3 in my server, and a 4k transcode in Plex keeps it about 30-35% busy.

I've decided to instead use ffmpeg to create a 1080p version of my 4k movies and load both into Plex. That way the Plex server doesn't need to do it on-the-fly. When converting, be sure to think about whether your 4k source is HDR and if you want your 1080p to be HDR or SDR.

 

[Dan Tudora]

hello
good point
use what you have and make to work

 

[joeschmuck]

I've decided to instead use ffmpeg to create a 1080p version of my 4k movies and load both into Plex. That way the Plex server doesn't need to do it on-the-fly. When converting, be sure to think about whether your 4k source is HDR and if you want your 1080p to be HDR or SDR.

I have said this type of thing many times before, create a second lower resolution where less or no transcoding is required and the typical response is "it takes up too much space if I retain the original 4K video as well."

To be honest, and this is just my opinion and others would argue otherwise, I think it's not cost effective to build a server primarily to store a huge video library. I can see in certain situations where if videos are played often or maybe you have kids that you don't want to touch your DVD/BlueRay collection, but typically that would be little kid movies and content so fairly a small amount of data, and the kid movies do not need to be in 4K either. I have about 100 movies and will be thinning those out over the Christmas break, hopefully I'll get that down to less than 40. I have grandkids who come over and watch many of the movies (Note that with Disney+ I have all those movies plus move now), otherwise I think I have a dozen that I tend to watch when I get the itch (generally when I see it playing on live TV and I want to watch and skip the commercials and not miss whatever they cut out.) 50% of my storage is backups, less than 5% is videos and not a massive video library, and I have about 45% free space. Sorry for ranting.

 

[ChrisRJ]

I cannot see a rant here

It probably just comes down to personal preference. Also, the size of the library will play a role. If I have 200 GB of videos and a small CPU, getting a bigger CPU for live-rendering will not make much sense. But if my video library is 30 TBs it's a different story.

 

[G8One2]

PLEX favors higher clock speeds for transcoding. SO.... look for a CPU that has 3Ghz or more with 6 or more cores. Some CPU's have integrated graphics controllers. Intel Quick SYNC works quite well if you can find a compatible CPU that does that for hardware offloading.

 

[Herr_Merlin]

Why not go gpu?

 

[G8One2]

Why not go gpu?

FreeNas does not have drivers for a GPU that I'm aware of. FreeNas typically needs server grade hardware.

 

[Herr_Merlin]

FreeNas does not have drivers for a GPU that I'm aware of. FreeNas typically needs server grade hardware.

Intel iGPU works. Some got it working with a random Nvidia as well.

Just search forum

 

[Dan Tudora]

hello
maybe is another way (in ALPHA stage but promising )
what about https://www.reddit.com/r/truenas/comments/ina1wc/truenas_scale_plex_hw_transcoding/

 

[pschatz100]

What are the devices that you are using for 4K playback? If they are 4K compatible Firesticks or Rokus, or newer TV's, then you probably do not have to transcode - they render 4K and will allow you to direct stream the content, which means you won't need as much CPU on your server. I use Rokus on all my TV's and the Xeon E3-1240V2 in my system does OK.