Hello, I have written a lattice boltzmann based parallel code for solving natural convection with MPI library. It is not my first time programming with MPI but this time I've got a problem that is when I run my code in one computer and using virtual parallel processing(I mean in one computer I set the MPI_size more than one) it works right but when I run it in a real parallel computer network (9 node) it doesn't work. I do need some help, I will be most grateful if some body could help me. Thank you very much Niavarani

Hello It may cause of your different compilers or MPICH or LAM package. Try to compile it with another compilers such as PETSc. It links with MPICH library, and in this case use include<petsc.h> instead of include<mpi.h> hope this helps Banaeizadeh