Hi, I am running a physics based boundary layer model with parallel code which uses openmpi libraries. I installed openmpi. I am running it on general purpose Azure machine with 8 cores, 32GB RAM. I compiled the code with *gfortran -O3 -fopenmp -o abc.exe abc.f* and then *mpirun -np 8 ./abc.exe* But i found slow speed with 4 and 8 cores. I also tried it with trial version of intel parallel studio suite, but no improvement in the speed.
why this is happening? is the code not properly utilize mpi? does it need HPC machine on Azure? Does it compiled with intel ifort? your suggestions/comments are welcome. Thanks and regards. Mahesh
