CPU for Plex Media Server? (4k transcoding)

Scramz · 1 Sep 2017 at 23:52

To put it into perspective, the R7 1700 will transcode a 4k HEVC at the original quality and transcode 3 1080p down to 2Mbps 720p with no stutter. I will try more streams at one time tomorrow so you can get a better idea if you would like me to.

R7 1700 is way inside the realms of 4k transcoding, with a hair off 2x encoding, there is a lot of head room left in the tank for multiple streams let alone one 4k stream.

Unless there is a different situation you would like me to test?

To note, hardware transcoding has a very noticeable reduction is visual quality. Software transcoding is, if not, almost identical.

Scramz · 2 Sep 2017 at 00:27

voidshatter said:
Wow! Wait, are you saying that a single E3-1225v3 can simultaneously transcode two 4k streams???

Could you help me run a benchmark test if you have time? Download this video, add it to Plex library, start a stop-watch, optimize it for "Mobile", and record how many seconds or minutes it takes to complete the optimisation. Thanks

R7 1700 encoding your download video above. Took just over 1 min with 1 other video transcoding at the same time and with 65ish% CPU Utilisation.

voidshatter · 2 Sep 2017 at 00:28

Randall8686 said:
Correct you can install synology OS onto any hardware although it runs better on Intel based products.

Don't they limit the functions (e.g. VideoStation transcoding) if they detect the MAC addresses/serial number to be not that legit?

Scramz said:
On a Ryzen 1700, these videos in Edge has 15-20% CPU usage and upwards of 60-70% in chrome. Chrome is rubbish at playing them.

Holy crap you just refreshed my knowledge - my dual core ultra-thin laptop can now play 8k videos without stuttering, just because you persuaded me to try Edge...

Scramz said:
I am running a R7 1700 at 3.6Ghz on all cores

This now looks tempting again! Thanks for posting and it appears that I should still take a serious consideration of the Ryzen 1700. Now I just need to figure out how to get one with good overclockability so that I can perhaps undervolt it for passive fanless cooling.

Scramz · 2 Sep 2017 at 00:31

voidshatter said:
Don't they limit the functions (e.g. VideoStation transcoding) if they detect the MAC addresses/serial number to be not that legit?

Holy crap you just refreshed my knowledge - my dual core ultra-thin laptop can now play 8k videos without stuttering, just because you persuaded me to try Edge...

This now looks tempting again! Thanks for posting and it appears that I should still take a serious consideration of the Ryzen 1700. Now I just need to figure out how to get one with good overclockability so that I can perhaps undervolt it for passive fanless cooling.

Just in case you missed it, I just posted above your requested test https://forums.overclockers.co.uk/posts/31117922. Bare in mind that a Ryzen CPU will be all software transcoding/encoding which will retain much higher quality than any hardware encoding like quick sync/nvsync.

My 1700 at 3.6 is also undervolted to 1.112v so it runs very cool and lower than 65w. If I get time tomorrow I can photograph of the power being pulled from the wall when transcoding 4k 265 with it undervolted and stock. It is very impressive, to say the least.

Nearly all 1700's will run at 3.6Ghz on all cores with no changes to the stock volts. You would have to be extremely unlucky to not get that.

I got mine to run at 3.2Ghz on sub 1.0v which was insanely cool and would 100% run on fanless cooling I would assume.

Scramz · 2 Sep 2017 at 00:42

HEADRAT said:
My thoughts are why are you trancoding 4K video on the fly, wherever possible you should be direct steaming.

Why not just use the optimise feature to create a video file that can be played by clients that aren't able to direct stream 4K h265

Hard disc space is much cheaper than a big CPU with all the heat/power/noise that it will end up bringing to the Plex Server.

If you have a HEVC compatible device and plex is still transcoding to it (which most have this issue) then just make a straight swap with the container from MKV to MP4 (nice and faster instead of re-encoding it) and it will play without an issue and no transcoding. Plex devices do not seem to like 265 in MKV containers at the moment.

Re-encoding a 265 40GB file to 264 will result in a 100gb+ file.

voidshatter · 2 Sep 2017 at 00:55

Scramz said:
To note, hardware transcoding has a very noticeable reduction is visual quality. Software transcoding is, if not, almost identical.

Totally agreed - software transcoding is way more flexible and does not depend on format/codec support that much.

Scramz said:
Just in case you missed it, I just posted above your requested test

I've just noticed it - many thanks for testing and it's very impressive time! Just a few more questions if you don't mind:

a) Are you absolutely sure that Plex has never used your GTX 1070 in stealth for any kind of hardware acceleration for the transcoding?

b) If I was to pick Crucial 32GB Kit (2x 16GB) DDR4-2400 ECC UDIMM VLP, will this significantly affect the transcoding performance, since Ryzen's performance depends so much on fast DIMMs such like 3400C16 or 3200C14?

c) Any suggestions for how to obtain a gem for undervolting whist maintaining the stock frequencies (or 3.6GHz on all cores, if that's required for 4k transcoding of some strange formats)?

Scramz · 2 Sep 2017 at 01:15

voidshatter said:
Totally agreed - software transcoding is way more flexible and does not depend on format/codec support that much.

I've just noticed it - many thanks for testing and it's very impressive time! Just a few more questions if you don't mind:

a) Are you absolutely sure that Plex has never used your GTX 1070 in stealth for any kind of hardware acceleration for the transcoding?

b) If I was to pick Crucial 32GB Kit (2x 16GB) DDR4-2400 ECC UDIMM VLP, will this significantly affect the transcoding performance, since Ryzen's performance depends so much on fast DIMMs such like 3400C16 or 3200C14?

c) Any suggestions for how to obtain a gem for undervolting whist maintaining the stock frequencies (or 3.6GHz on all cores, if that's required for 4k transcoding of some strange formats)?

A) Zero help from the GPU, see GPU utilisation below.

B) Ryzen doesn't depend so much on RAM. Only gaming but even then thy are minimal gains. 2400 to 3200 will see hardly any improvements over transcoding.

EDIT: changed my RAM to 2400 from 3200Mhz with no visible impact to performance. If moving from 3.6Ghz to 2.5Ghz didnt really hit performance then that RAM speed adjustment won't either.

C) You don't need a gem, to put it into perspective I quickly dropped the CPU clocks to 2.5Ghz on all cores which is waaayyyy below stock clocks as you can see from Task Manager in the below screen grab and it is handling 4k transcoding with ease, to the point it is even throttling the transcode. Sub 2Ghz would proberly transcode 4k fine, 16 threads is nothing to be sniffed at.

It is even settling encoding at about 1.7x (below) hitting 2.4x and 1.4x jumping.

Don't underestimate the 1700 at these workloads. I would be surprised if the R5 1600 would handle 4k with ease too whilst sipping so little power.

EDIT: 265 is very inefficient, these CPU's destroy 264 files.

Scramz · 2 Sep 2017 at 01:24

Below, I even did your video test on 2.5Ghz, finished in 1 min 12 sec.

voidshatter · 2 Sep 2017 at 01:32

Scramz said:
A) Zero help from the GPU, see GPU utilisation below.

B) 2400 to 3200 will see hardly any improvements over transcoding.

EDIT: changed my RAM to 2400 from 3200Mhz with no visible impact to performance. If moving from 3.6Ghz to 2.5Ghz didnt really hit performance then that RAM speed adjustment won't either.

C) You don't need a gem, to put it into perspective I quickly dropped the CPU clocks to 2.5Ghz on all cores which is waaayyyy below stock clocks as you can see from Task Manager in the below screen grab and it is handling 4k transcoding with ease, to the point it is even throttling the transcode. Sub 2Ghz would proberly transcode 4k fine, 16 threads is nothing to be sniffed at.

Below, I even did your video test on 2.5Ghz, finished in 1 min 12 sec.

It is even settling encoding at about 1.7x (below) hitting 2.4x and 1.4x jumping.

Don't underestimate the 1700 at these workloads. I would be surprised if the R5 1600 would handle 4k with ease too whilst sipping so little power.

Looking to get the following parts hoping for a fanless media server. Not sure whether it'll work but you are giving me much hope to control the TDP well below 50W! I'll need a gem as good as I can get so I can undervolt as much I can. Since it's a fanless system, I'll need all the undervolting headroom I can get!

The plan is to get the rig up and running Linux without a graphics card (well maybe install the OS with a graphics card) then plug it to the router and only use SSH to control it. In the future maybe I'll slot in an R9 nano (or Vega 64 nano if it will exist/edit: just released), but that would violate the fanless criteria.

I'm a bit worried about the motherboard - the 8-pin location is crap and would require customised replacement cable. I'm also not sure whether the location of the CPU socket would cause any issues with the relatively big cooler in a small case. Will this motherboard work well with Ryzen 1700 for undervolting purposes?

Scramz · 2 Sep 2017 at 01:36

voidshatter said:
Looking to get the following parts hoping for a fanless media server. Not sure whether it'll work but you are giving me much hope to control the TDP well below 50W! I'll need a gem as good as I can get so I can undervolt as much I can. Since it's a fanless system, I'll need all the undervolting headroom I can get!

The plan is to get the rig up and running Linux without a graphics card (well maybe install the OS with a graphics card) then plug it to the router and only use SSH to control it. In the future maybe I'll slot in an R9 nano (or Vega 64 nano if it will exist/edit: just released), but that would violate the fanless criteria.

I'm a bit worried about the motherboard - the 8-pin location is crap and would require customised replacement cable. I'm also not sure whether the location of the CPU socket would cause any issues with the relatively big cooler in a small case. Will this motherboard work well with Ryzen 1700 for undervolting purposes?

Ryzen cpus need a gpu as there is no igpu.

I don't know much about the motherboards bios sorry. I'm just handing you the numbers/performance of the chip. Don't get bogged down with pass mark, different codecs require different CPU grunt regardless of pixels and scores.

One thing for sure, Ryzen CPUs will give you better performance per watt over intels with software transcoding.

jigger · 2 Sep 2017 at 18:57

It's a server You don't need a graphics card.

muon · 2 Sep 2017 at 19:00

jigger said:
It's a server You don't need a graphics card.

I doubt normal motherboards will boot without a GPU or IGP.

jigger · 2 Sep 2017 at 20:01

Sure they will.

DragonQ · 2 Sep 2017 at 20:02

muon said:
I doubt normal motherboards will boot without a GPU or IGP.

Maybe but any old card will do. If you really don't have one lying around then grab a used one or get one of the el-cheapo HTPC ones for £25.

jigger · 2 Sep 2017 at 20:13

After the install and setup you run headless. No need for a video out after that point.

DragonQ · 2 Sep 2017 at 20:40

jigger said:
After the install and setup you run headless. No need for a video out after that point.

Yes and what would you use for setup?...

jigger · 2 Sep 2017 at 20:55

Any card you have.

voidshatter · 2 Sep 2017 at 21:20

DragonQ said:
Yes and what would you use for setup?...

Maybe a spare 980. Then unplug it abd use it
As per the title of this thread says

DragonQ · 2 Sep 2017 at 22:07

jigger said:
Any card you have.

Which is what I said.

jigger · 3 Sep 2017 at 00:03

You don't need a graphics card to run a system. The system will boot just fine without one.