Multicore programming - what do I use?

[helstreak]

So I have a quadcore and I would really like to use all the cores to run a simulation. I have experience with parallel programming on a cluster that's already set up with MPI however my computer doesn't have that. I'm wondering, in order to use all my cores do I need MPI or is there anything else?

Thanks for your help :)

[MadCow108]

depends on the language
pthreads or openMP for C
boost threads or openMP for C++
openMP is also available for Fortran

openMP is probably the easiest. Especially if all work is done in few loops with little synchronization, a common situation in simulations.

[shadylookin]

If you just make it multithreaded the scheduler should utilize all your cores. On linux with C/c++ you can use the pthread library to do this.

[cholericfun]

openMP is designed for Shared Memory Processors like a quad-core.
MPI is for distributed memory, however you can run MPI on an SMP. as far as i understand, MPI would produce a copy of your program for every core whereas openMP will keep redundant data to a minimum.

heres a little script to run openmp compiled files (from some webpage about openMP) :

#!/bin/bash
#usage: trun [myexe] [threads]
set -u
MYEXE=$1
export OMP_NUM_THREADS=$2
echo "Running $MYEXE on node 'hostname' \
with $2 threads"
$MYEXE
exit

get a few examples to look at and you'll be fine, openmp is not that bad to learn.