First at all, MPI must be installed on your running machine.
- Then compile with the "key_MPI_2D" CPP key and set "FC = mpiifort" in your Makefile.caparmor.
- Prepare your "mpi.txt" file (see mars_decoupe_manual on internet website)
- Run tho code with the command runmpi_connect
- runmpi_connect jobname outputname nbproc 1/2 (see mars_envir_manual)
- nbproc is the number of CPU you want to use, it must be equal to "nb actifs" which is written on the 5th line of the mpi.txt file.
If there is no mpi.txt file, the job runs with MPI, but the domain is not divided in 2D with squares (or rectangles) but in 1D with strips. Strips are vertical (horizontal) if imax (jmax) is larger than jmax (imax respectively).
This answer is correct for V8.19 but the compilation and the launch of the job are slightly different in V9.05 (see)