Running phantom with MPI
Installing MPI
To compile phantom with MPI, you will need an MPI distribution installed. On your local machine you can install openMPI:
Ubuntu
sudo apt-get install openmpi-bin openmpi-common libopenmpi-dev
Mac OS
brew install openmpi
Compiling Phantom with MPI
Follow the usual procedure but with MPI=yes, i.e.:
mkdir mycalc
cd mycalc
~/phantom/scripts/writemake.sh disc > Makefile
export MPI=yes
make setup
make
Running the code with MPI
This is the same as usual but pre-pended by “mpiexec -np 4” where 4 is the number of MPI threads
./mpiexec -np 4 ./phantom disc.in
Running on a cluster
On a supercomputing cluster, you can amend your queue script as necessary by writing it with MPI=yes. For example, on the gadi machine with 2 MPI threads and 48 openMP threads (96 cpus in total) you would use:
make qscript MPI=yes NOMP=48 NMPI=2 > run.q
qsub run.q