Does matlab create only one worker on each core when you use parallel toolbox?

I have R2011b, use parallel toolbox and wanna know how it duplicates workers. Is it supposed to create just one worker on each core?

Answer 1

[Edric Ellis]

Yes, that's right - the default is to use the number of physical cores (not hyperthreaded cores). You can override this choice by setting the NumWorkers property of the local scheduler.

[m r]

thanks a lot. so I can have workers more than the number of my physical cores; but is there any upper limit for number of workers?

[Edric Ellis]

Yes, in R2011b the limit is 12 for the local scheduler. If you upgrade to R2014a or later, this limit is removed. (There is no limit in R2011b if you use MATLAB Distributed Computing Server workers).

[m r]

I appreciate it

[Sean de Wolski]

The Parallel Computing Toolbox doesn't assign workers to cores, the OS does as system resources become available.