Re: compare the executive speed with Matlab

[Sergei Steshenko]

--- On Fri, 1/2/09, John W. Eaton <address@hidden> wrote:

> From: John W. Eaton <address@hidden>
> Subject: Re: compare the executive speed with Matlab
> To: "wim van hoydonck" <address@hidden>
> Cc: address@hidden, address@hidden, "Howard" <address@hidden>
> Date: Friday, January 2, 2009, 2:45 PM
> On  2-Jan-2009, wim van hoydonck wrote:
> 
> | To conclude, on my computer, for this test, Octave is
> approximately
> | as fast as C, gfortran is a little bit faster and ifort
> is 10 times as fast.
> | 
> | If you want to speed up your code, write the critical
> parts in Fortran, not C.
> 
> I don't think that conclusion is justified, but
> whatever.  Clearly it
> is not the language alone, or gfortran would also be 10
> times
> faster...
> 
> In any case, I'm surprised by the 10 times factor.  So
> how about
> comparing the assembly code that is generated.  What is
> ifort doing
> that the others are missing?
> 
> jwe

Intel compilers are known to very effectively utilize SSE* instructions,
and at all timing/pipelining.

Regards,
  Sergei.