Hi Erin, > I have a dual core laptop and I would like to have both cores running. > > Here is the following my-hosts file: > localhost slots=2
Be warned that at least in default config running more MPI threads than you have cores results in dog slow code. Single core machine: $ cat my-hosts localhost slots=1 $ mpirun -np 1 -hostfile my-hosts ./sort selectionsort 1024 1024 0.009905000seconds $ mpirun -np 2 -hostfile my-hosts ./sort selectionsort 1024 1024 4.113605000 seconds (on dual core both -np 1 and -np 2 run almost equally fast (only slightly speedup due to poor algorithm (developed for demonstration purposes)) Best regards Fabian
