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Re: compare the executive speed with Matlab
From: |
John W. Eaton |
Subject: |
Re: compare the executive speed with Matlab |
Date: |
Fri, 2 Jan 2009 16:03:15 -0500 |
On 2-Jan-2009, Sergei Steshenko wrote:
| Sure, sure.
|
| 1) 'octave':
|
| octave:36> angles = pi * (1:1000000) / 1000000;tic; sins = sin(angles); toc
| Elapsed time is 0.49532795 seconds.
Please, use cputime. Wall clock time is meaningless here as there
could be other things running on your system which affect the timing.
| 2) "C":
|
| CPU time took 0.13 seconds at line number 74 of 'benchmark_sin.c' file
| Wallclock time took 0.130743 seconds at line #74 of 'benchmark_sin.c' file
|
|
| ; the file is attached ('benchmark_sin.c'), it contains the command line
| I used to compile it.
|
| OK, so it's not 5 times, it's more than 3 times.
|
| I think, however, that if I use table representation of 'sin', the ratio
| will be the 5 times I vaguely remember.
So, how did you build Octave, and what version is it?
Here is what I see with Octave 3.0.3 on a Debian AMD64 system. My
copy of Octave is installed from the Debian package and used GCC 4.3.2
(Debian 4.3.2-1) with -O2 (and no other tricky optimization flags):
octave:1> angles = pi * (1:1000000) / 1000000;
octave:2> t = cputime (); sins = sin (angles); cputime () - t
ans = 0.072004
Here is what I see with your code using the same version of GCC
$ gcc -mtune=native -march=native -O3 sin-tst.c -lm -lrt
$ ./a.out
CPU time took 0.05 seconds at line number 74 of 'sin-tst.c' file
Wallclock time took 0.0685717 seconds at line #74 of 'sin-tst.c' file
So I don't really see anything to fix here.
jwe
- compare the executive speed with Matlab, Howard, 2009/01/01
- Re: compare the executive speed with Matlab, Michael Goffioul, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, John W. Eaton, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, Jordi GutiƩrrez Hermoso, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, John W. Eaton, 2009/01/02
- Re: compare the executive speed with Matlab, Jordi GutiƩrrez Hermoso, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab,
John W. Eaton <=
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, wim van hoydonck, 2009/01/02
- Re: compare the executive speed with Matlab, John W. Eaton, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, Sergei Steshenko, 2009/01/02
- Re: compare the executive speed with Matlab, wim van hoydonck, 2009/01/05
- Re: compare the executive speed with Matlab, John W. Eaton, 2009/01/02