Hello everyone! I’m a beginner and I’d like to use NEMO as a benchmark to test my HPC system and CPU. My system has 2 sockets, 80 physical cores and 160 logical cores. I use MPICH 4.2.0 and NEMO 4.2.2.
When I run the command:
OMP_NUM_THREADS=2 OMP_PLACES=threads OMP_PROC_BIND=spread mpirun -n 80 --map-by socket:PE=1 ./nemo
the CPU utilization is only 50.8% but I think the ideal CPU utilization should be 100%. And if I set OMP_NUM_THREADS as 1, the CPU utilization is still 50%. I’ve also tried a few other settings but none of them got what I thought.
I don’t know why. I’m guessing if the variable settings of OMP work for NEMO.
Does NEMO support OpenMP? What should I do if I want to test the impact of hyperthreading on NEMO?