CPU for Plex Media Server? (4k transcoding)

voidshatter · 11 Aug 2017 at 14:50

muon said:
When did Passmark represent transcoding?

As other have said, why would you be transcoding 4K to 4K on the fly? Seems bizarre as it won't be lossless.

Checking http://wayback.archive.org, the following description by Plex has existed since May 2016.

Do you think transcoding 4k to a mobile device or a smaller 1080p TV would be a good enough reason?

Orcvader · 11 Aug 2017 at 14:51

voidshatter said:
If I want to stream over the local network, not via the output cable of a graphics card, will GPU acceleration work?

Yes. It won't need to outpout anything, it'll just be using the media decoder on the GPU. The GPU will need to support HEVC/h.265 decoding for 4K however...

voidshatter · 11 Aug 2017 at 14:57

ZXSpectrum said:
I would say that would work fine! I am a big advocate of utilising older tech for home media server use, I have a fully stacked Xeon system 8 core 16 thread 2.6Ghz (Turbo to 3.3) 16Gb of DDR3 1333Mhz ECC Reg, Intel S2600CO4 motherboard, Intel 4U Pedestal/Rackmount Chassis and a Intel Server 500W PSU. Granted I did get some parts for nothing as they are old tech but even so they make fantastic, stable servers that can be utilised for a variety of home server use and are reasonably cheap.

A single Xeon E5-2670 should score about 12k in Passmark and should stutter for 4k transcoding if what I'm reading is correct. Two of these would bump the TDP to 230W, when compared against the 95W of a single Ryzen 1800X. Do you find the Rackmount Chassis running quiet enough? I'd like it to be put probably under the TV and don't want too much interference lol

Orcvader said:
The GPU will need to support HEVC/h.265 decoding for 4K however...

Interesting! Any reliable link to get a list of such GPUs?

Panos said:
Why you jump from 1950X to 7601?
there is the 7401 for $1100 and 24 cores. And 7551 for $2100, a 32core cpu

I was kidding when I quoted an AMD Epyc. I don't think I can handle the cooling or electric bill for it yet

But you are right, a 7401 should be looked into!

Orcvader · 11 Aug 2017 at 15:07

voidshatter said:
Interesting! Any reliable link to get a list of such GPUs?

Not really any solid lists but pretty much all the Nvidia 10 series and AMD 400/500 series can do HEVC decoding.

voidshatter · 11 Aug 2017 at 15:14

Orcvader said:
Not really any solid lists but pretty much all the Nvidia 10 series and AMD 400/500 series can do HEVC decoding.

Thanks! I still remember that when I had a laptop with Core 2 Duo over a decade ago, I had to configure nVidia's proprietary decoder (something called PureVideo?) in order to enable GPU accelerated playback for some 1080p videos with high bit-rates and mitigate the CPU load. However, there were always compatibility issues for certain videos from time to time. Will it be easy enough to configure Plex to utilise such modern GPUs?

Orcvader · 11 Aug 2017 at 15:18

Honestly I don't really have any experience with this using Plex. As a few others I found just playing the video directly worked best but then again I don't have any 4K TVs.

A quick search brings this up so Plex transcoding with HEVC/h.265 may not work, although that was more than a year ago so no idea if it's been updated to support it now: https://www.reddit.com/r/PleX/comments/5k2bpo/plex_now_does_hw_transcoding_hardware_transcoding/

EDIT: A more recent update, it still seems limited to Intel IGPs: https://www.reddit.com/r/PleX/comments/6t0qj6/plex_media_server_hardware_transcoding_preview_4/

DragonQ · 11 Aug 2017 at 15:23

Orcvader said:
Not really any solid lists but pretty much all the Nvidia 10 series and AMD 400/500 series can do HEVC decoding.

Anything with nVidia's VP8 (Feature Set H) so even a GT 1030 should do it in up to 8K. AMD's more recent cards can't do 4K at anything over 30 fps supposedly so I'd go nVidia for this.

I have no idea if Plex allows you to use GPU encoders natively though.

ZXSpectrum · 11 Aug 2017 at 15:29

voidshatter said:
A single Xeon E5-2670 should score about 12k in Passmark and should stutter for 4k transcoding if what I'm reading is correct. Two of these would bump the TDP to 230W, when compared against the 95W of a single Ryzen 1800X. Do you find the Rackmount Chassis running quiet enough? I'd like it to be put probably under the TV and don't want too much interference lol

I understand what you are saying but you would almost get the entire system for the price you would pay for the 1800X alone

My server is in another room, it has 12 hard drives so it was never going to be quiet so it doesn't bother me at all.

Chaos666 · 11 Aug 2017 at 16:16

is price for 4k transcoding really that high? My poor core 2 duo 8600 freenas server works fine with 1080p videos but its dying when I throw a 4k video at it.
I was hoping something like i5 3570 or i7 3770 will be ok ... but i see You guys are talking about ryzen 1700 :O ..... is there really no hope for something cheaper? :>

voidshatter · 11 Aug 2017 at 16:23

Chaos666 said:
core 2 duo 8600 freenas server works fine with 1080p videos

Core2 Duo E8600 scores 2400 in PassMark, which is just above the recommended requirement of 1080p transcoding by Plex.

You'll need something scoring above 15,000 in PassMark (or even 16,000 as recommended by Plex employee), which means Ryzen 1700, Ryzen 1700X, Coffee Lake 8700 and Coffee Lake 8700K will all stutter for 4k transcoding. Overclocking the Ryzen 1700 may also be an option, though stability would be in question.

As mentioned by ZXSpectrum, older Xeons may serve well. However, electric bills would be another story.

Chaos666 · 11 Aug 2017 at 16:27

I'll pass on 4k streaming for now ... maybe they will figure out gpu encoding soon.. :>

p.s: I just checked .... my 4.5GHz 3770k gets 11500 in passmark

benjii · 14 Aug 2017 at 13:14

I'm clearly missing something here. Why would you pursue transcoding at that cost, when you could buy a £50 Intel G4560 and stream 4k directly? I have one in my HTPC and it handles 4k 60fps like a champ.

moogle · 14 Aug 2017 at 14:04

benjii said:
I'm clearly missing something here. Why would you pursue transcoding at that cost, when you could buy a £50 Intel G4560 and stream 4k directly? I have one in my HTPC and it handles 4k 60fps like a champ.

Although @OP hasn't said it, he might be watching on a device that can't view 4K footage.

MG42Maniac · 18 Aug 2017 at 10:28

I posted a thread here asking this same question. I've decided to go down the route of Optimised Versions. I figured what is a few extra GB on 50/60GB. I think the CPU requirements are just far too high. I'd be interested in a GPU that took the workload off the CPU though.

voidshatter · 18 Aug 2017 at 17:15

Looking into similar performance (around the minimum requirement) and similar TDP, Intel's offering is significantly more expensive than AMD's. Anyone can point me to a decent ITX motherboard for Ryzen 1800X, with at least one M.2 slot, as well as (unofficial) support of ECC memory?

voidshatter · 19 Aug 2017 at 00:35

Looking into some benchmarks related to transcoding, I've found that the Ryzen 1800X may not perform as well as it's supposed to be able to. Speculations would be the optimisations of software utilising specific instruction sets. This means the 1800X build may fail for real-time smooth 4k transcoding on certain video codecs with certain transcoders. Any Ryzen users here can confirm how it works with Plex, preferably with tests on various 4k videos? Unless I can see some real-world use cases, I tend to wait until Intel releases their E3-1200 v7 series based on Coffee Lake and see how these will perform.

GWANGY · 19 Aug 2017 at 12:27

surely native 4k footage ?? is gng to be a lot more than 50/60gb , as that is the size of a std bluray image. I certainly wouldnt trust raw passmark figures to give you a guide as most modern cpus , except xeons, have a decnt set of video decoding blocks built in regardless wether they have video capabilitys . the ability to decode the format (x264,x265,vp8,9) you require in HARDWARE rather than software will make a massive difference 1000%.
If you are not playing back 4k now then just settle for a good 1080p solution. And upgrade when the cows come to roost

voidshatter · 19 Aug 2017 at 16:33

GWANGY said:
I certainly wouldnt trust raw passmark figures to give you a guide

I have just realised this... I've just done some tests on Alpine AL-514 in my current NAS, and it appears that while it transcodes 1080p at almost 100% CPU load, some formats/codecs play smoothly (with transcoding) while some certain formats/codecs would stutter from time to time. It wouldn't be a good idea to purchase something near the mininum requirement only to find it stutters for certain videos, so no the Ryzen 1800X is not a reassuring choice.

I'll wait for Coffee Lake and see whether there's any viable option for fanless passive cooling.

muon · 19 Aug 2017 at 16:53

Mate you only created this thread to rationalise why Ryzen is crap.

x264 handbrake runs have 2 passes, the first of which runs far more quickly does not utilise lots of cores very well. That is why the higher core counts don't give a massive advantage. Pass 2 which takes up most of the time of a handbrake x264 encode shows the benefit of having multiple cores.

x265 encoding right now on free software is massively innefficient at the moment. Coffee lake won't magically get past that.

gavinh87 · 19 Aug 2017 at 18:05

Hidden agenda.