[FFmpeg-user] Best CPU for ffmpeg

[Carl Eugen Hoyos]

Tim Nicholson <nichot20 <at> yahoo.com> writes:

> > Did you ever test to start all your instances with 
> > -threads 1 (twice, once for decoding, once for 
> > encoding)?
> 
> as in ffmpeg -threads 1 -i infile -threads 1 ...outfile ?

Yes.
(Although the effect is possibly decoding-only.)

> > I wonder if that wouldn't increase performance, in 
> > some cases even significantly.
> 
> So, just to clarify, are you suggesting that in cases 
> where some processes don't multithread properly

No.

> you force the whole chain to single thread (and then 
> run multiple instances)?

Assuming you don't want to encode one file but many files 
n with n larger than the number of CPU cores in your 
hardware, I wonder if it isn't (significantly?) faster to 
encode all n files (no matter if multithreading works 
well for them or at all) if you always use -threads 1.
Or in other words: I believe that multi-threading has a 
measurable overhead - at least in some cases.

But maybe the overhead I mean is non-blocking and it 
simply makes no difference.

Carl Eugen