Thread Subject: Number of CPUs on machine

Hi,
I am wondering if there is a Matlab command to determine the
number of CPUs on a machine. I am writing a program for
parallel execution and there are some parameters which
depend on the number of CPUs available.

Thanks in advance.
Bobane

"EUSTACE " <bobane73@hotmail.com> wrote in message
<f9si3c$cck$1@fred.mathworks.com>...
> Hi,
> I am wondering if there is a Matlab command to determine the
> number of CPUs on a machine. I am writing a program for
> parallel execution and there are some parameters which
> depend on the number of CPUs available.
>
> Thanks in advance.
> Bobane
>

feature('numCores');
Note: feature is undocumented/unsupported
Also note that you need to turn Matlab's multithreading on
(Preferences/General/Multithreading)

Yair Altman
http://ymasoftware.com

If you use sparse x=A\b, expect multithreading to slow your
code down (see the latest Cleve's Corner). The problem is a
bug in the multithreaded BLAS.

> > I am wondering if there is a Matlab command to determine the
> > number of CPUs on a machine. I am writing a program for
> > parallel execution and there are some parameters which
> > depend on the number of CPUs available.
> >
> > Thanks in advance.
> > Bobane
> >
>
> feature('numCores');

Well, he seems to be asking about the number of CPUs
available. If multithreading is enabled, the answer to this
question would be given by

getNumberOfComputationalThreads

on R2007a.

Or, if you're using an older Matlab version on a *nix
system, try

getenv OMP_NUM_THREADS

Joachim

"John Vendt" <a@B.dot.com> wrote in message
<f9sucs$6gd$1@fred.mathworks.com>...
> > > I am wondering if there is a Matlab command to
determine the
> > > number of CPUs on a machine. I am writing a program for
> > > parallel execution and there are some parameters which
> > > depend on the number of CPUs available.
> > >
> > > Thanks in advance.
> > > Bobane
> > >
> >
> > feature('numCores');
>
> Well, he seems to be asking about the number of CPUs
> available. If multithreading is enabled, the answer to this
> question would be given by
>
> getNumberOfComputationalThreads
>
> on R2007a.
>
> Or, if you're using an older Matlab version on a *nix
> system, try
>
> getenv OMP_NUM_THREADS
>
> Joachim

Hi guys,
Thanks guys for your suggestions. Yes, I just wanted to know
how many processors were available without the
multithreading (am using R2006b on Windows XP), and working
from Joachim's suggestion, I have found the solution I wanted:
    getenv('NUMBER_OF_PROCESSORS')

Thanks again.

Bobane

EUSTACE:
<SNIP housekeeping his/her cpus...

> command to determine the number of CPUs on a machine...

another one of the many solutions

     import java.lang.*;
     r=Runtime.getRuntime;
     ncpu=r.availableProcessors
% -also- see
     methods(r)
% for other informations you can get from <r>...

us