Server CPU for x265

[TEB]

hi. Im trying to figure out what Intel or AMD cpu in the server space (Xeon type) that will give a good speed vs. cost.
Intel Xeon E5-2650v4 is based on the broadwell platform, but will give 12cores each physical cpu.
How does this one compare on x265 and x264 vs. the consumer cpus that most of the people here use?
Or are there other newer Xeons that i can procure for this job?

br TE

[microchip8]

neither x264 nor x265 will be able to saturate all cores, from 10/12 cores and up. You will have to run two encodes at once for 100% saturation. Also, if you consider a Xeon, also consider an AMD Threadripper/Epyc. Won't cost an arm and a leg

[Atak_Snajpera]

For FullHD x264 might be able to saturate 24 threads. Assuming that you do not have any bottleneck during decoding/processing frames (for example in AviSynth). x265 is a different story. Like froggy said you will have to run two x265 encoders to get full saturation.

[TEB]

thx for the response ;)

1. Threadrippers look nice, but i need support for Lenovo X3550 server hw... (company rule..) so its gotta be xeons for now..
2. Gonna do multiple encodes concurrently yes..
3. Source will be IMX or Prores 4:2:2 via FFMPEG ->
4. Target will be ABR stack for Dash

[kolak]

When you run many instances then it all doesn't matter that much as you will be running at 100% about all the time. All what counts is overall processing power- cores*clock.
Not sure if there is a big difference between modern CPUs when it comes to speed/GHz. AMD maybe bit slower, but they are way cheaper, so for such a setup they will be most likely most cost effective. I would probably limit each transcode to 12-16 threads (in x264 settings) and run many simultaneous files, so whole setup is 100% loaded.

[kolak]

For FullHD x264 might be able to saturate 24 threads. Assuming that you do not have any bottleneck during decoding/processing frames (for example in AviSynth). x265 is a different story. Like froggy said you will have to run two x265 encoders to get full saturation.

Saturating cores is 1 thing, but using their potential is another. x264 as far as I remember is far from linear scaling with speed/ core. If 8 cores give you 100fps than 16 will never give you 200fps. You are way better running parallel encodes in such a case with each limited to 8 cores.

[Blue_MiSfit]

Right, and rate control gets harder / sometimes buggier with more and more threads.

I find that 8-12 threads is a happy medium in most cases. Though honestly if you're really scaling horizontally then single threaded is the way to go.

[kolak]

Yep, specially if you deal wit tons of files and don't need them in next 1h.

[TEB]

Update: We went for a dual Cpu Xeon Silver 4114 setup.

https://ark.intel.com/products/123550/Intel-Xeon-Silver-4114-Processor-13_75M-Cache-2_20-GHz

Question: Should one enable HT for X264/x265 encoding? IE: 20cores vs. 40 HT cores..

[kolak]

If you are going to do many simultaneous encodes than for sure. This will give you few %.
Even if not then it shouldn't really matter anyway. Keep it on.
I would just advice to limit number of threads per single encode to 8-12 or so if you do many files. This will much better use whole power of the machine. Letting x264 to use all threads per encode is not optimal when you have so many.

I don't like your choice :) Was it good deal?

[Atak_Snajpera]

I don't like your choice Was it good deal?

Recommended Customer Price $694.00 - $704.00
Looks pretty good if it is true. For example single EPYC 7551P (32C/64T) costs ~$2000

[TEB]

Well. preferably i would have gotten at threadripper setup, but im part of a big company, and Datacenter department has standardized on IBM servers... so... no threadripper for me..

http://www3.lenovo.com/us/en/data-center/servers/racks/Lenovo-ThinkSystem-SR630/p/77XX7SRSR63

Ill run the benchmark in this forum when i get it up´n running.

TEB

[Atak_Snajpera]

Ill run the benchmark in this forum when i get it up´n running.

This may scale better on this dual socket
http://forum.pclab.pl/topic/1184884-x265-FHD-Benchmark/

[Blue_MiSfit]

You'll get great performance on this guy as long as you can run multiple transcodes in parallel. You're gonna have a tough time trying to get a single stream in x265 to saturate that without MulticoreWare's special UHDKit software...

Maybe with a 4k stream you can do it?