Hi! I've tried reading up on this forum and throughout the documentation, without success and was hoping you could help me. I'm trying to run a software called LAMMPS on my personal computer (using an AMD Ryzen 7 1700X processor, could that be the source of my issues?), my goal is to make use of its 8 physical cores to accelerate the execution time of a single LAMMPS instance.
I use a function in the software's input script which sets the number of OpenMP threads for each MPI process to 1, as increasing this value drastically slows down the software. This is how I call the mpiexec function : mpiexec -ppn 1 -n 8 -localonly -genv OMP_NUM_THREADS 8 lmp_mpi -in Morse_Temp_1.in
I use the 2019 version of Intel Parallel Studio XE with a student license, if it can help :)
No matter what combination of values I put for -n or -ppn, my LAMMPS executable will either be run only once, using a single processor, or it'll be run 8 times in parallel, as in running 8 times the same calculations, effectively doing the same result (and performance) as a single processor, but 8 times simultaneously. What I'd want would be for the LAMMPS task to be divided across the 8 cores/16 threads available.
Thanks a lot :)