Does Intel Core 2 Duo mean 2 processors? When I use MPI subroutine MPI_COMM_SIZE I got size=1. Does it means that there are 1 processors?Andthe reason is that I useWinXP 32-bit? Can you please tell how to use 2 processors? Thanks, Thanh
No, MPI_COMM_SIZE doesn't tell anything about the number of processors, under either of the common definitions. Core 2 Duo is certainly capable of running 2 MPI ranks, or 2 OpenMP threads, even under XP32. Did you start your job by mpirun -np 2 or similar ? MPI implementations, in my experience, never pick a number of ranks automatically, unlike OpenMP, where some implementation default to 1 thread, and others default to total number of cores or logicals. Intel like to call a Core 2 Duo a single processor dual core, even though the term logical processors also is used, particularly for HT. Many MPI users consider dual core as 2 processors.