Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: [OMPI users] Basic question about MPI
From: Pradeep Jha (pradeep.kumar.jha_at_[hidden])
Date: 2013-01-29 00:16:48


I have a very basic question about MPI.

I have a computer with 8 processors (each with 8 cores). What is the difference between if I run a program simply by "./program" and "mpirun -np 8 /path/to/program" ? In the first case does the program just use one processor out of the 8? If I want the program to use all the 8 processors at the same time, then I have to do with mpirun?

Something fundamental is buggin me.

Thank you,