Intel MPI library question
 

looking at getting Intel parallel studio xe 2015.
there is 3 editions, composer, professional, and cluster.
only cluster has the intel mpi library according to this:
https://software.intel.com/en-us/int...llel-studio-xe

question is,
i run some software that gives me parallelization options specifically MPI types = pcmpi, intel, openmpi.

if i chose intel, then do i need the "intel mpi library"?
is intel mpi only provided by intel, available only in parallel studio cluster edition?
the other thing is clustered computing or distributed memory on a cluster, versus shared memory on a local machine.
for shared memory on a local machine, is intel mpi still relevant and better/faster than any of the other mpi types?

disregarding complex computer setups, let's say i have just a basic workstation that has 2 intel cpu's each having 6 cores. I want to write code that runs across all cores and all memory on that one motherboard,
do i need intel mpi? should i write it to use intel mpi? is the cost of intel parallel studio cluster edition worth the cost which gives me intel mpi library?

It would seem to me, yes, if you choose intel then you are choosing their implementation. Openmpi is free and available for Linux.