[FFmpeg-user] ffmpeg x265 on multi-cpus

Erik Slagter erik at slagter.name
Mon Apr 10 15:55:57 EEST 2017

> Am 10.04.2017 um 14:43 schrieb fred fred:
>> thank you Moritz !
>> anyway, even with -threads 0
>> x265 [info]: Thread pool created using 24 threadsx265 I see with top
>> command between 400% - 500% CPU on ffmpeg ... I was expected like
>> 2400% or 24 ffmpeg workers with 100%
> how did you come to the conclusion that parallelization scales magically
> and with no limits? if that would be realistic just throwing enough CPU
> cores on whatever problem would be the soplution - but that is not how
> computers are working

On the other hand, both libx264 and libx265 do scale quite well by
smartly dividing the work over all available threads. Yes, you can
really have up to 800% cpu usage on a 4x2 cpu (which is quite
impressive), with both of them.

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