[Ffmpeg-devel] Re: about mmx instructions

Rich Felker dalias
Thu Sep 1 19:49:41 CEST 2005

On Thu, Sep 01, 2005 at 07:15:01PM +0200, Balatoni Denes wrote:
> Hi!
> cs?t?rt?k 01 szeptember 2005 17.15-kor thomas.kunlin at free.fr ezeket a bolcs 
> gondolatokat fogalmazta meg:
> > A x2 speedup could be achieved by using the SSE2 integer
> > instructions (128bit registers instead of 64bit for MMX),
> > using the very same algorithm. I am working on it at this
> > moment.
> For older pentium 4s that is 25 % improvement at best . Perhaps the 
> performance of athlons (or newer pentium 4s) is better, I don't know.

The 2x claim is clearly nonsense, since (like basically all
operations) the process is memory-io-bound, not cpu-bound.. :)


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