[FFmpeg-user] ffmpeg x265 on multi-cpus

Erik Slagter erik at slagter.name
Mon Apr 10 16:02:43 EEST 2017

>>> 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
> but you can't expect that that scales up to every core count

But at least to more than eight cores (see the documentation), libx264
is (yet) a bit more scalable, but I guess libx265 will get better at it
as well. On a 2x2x12 core machine I had to start two concurrent
encodings to get all of the cpu's busy all of the time (libx265), but I
also must say it didn't really add that much to the total encoding frame

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