Increasing performance in molecular dynamics calculation

[icamps]

Hello.

My system has around 1200 atoms. I set up a molecular dynamic simulation using the GFNFF force field and launch xTB using:
(xtb version 6.7.1 (43a0e4e) compiled by 'runner@fv-az1269-365' on 2024-09-19)

export NUM_THREADS=18
export MKL_NUM_THREADS=${NUM_THREADS}
export OMP_NUM_THREADS=${NUM_THREADS},1
export OMP_STACKSIZE=15G
ulimit -s unlimited

This job was run in my notebook that has 20 cores. After launching the script, I change the job to the highest priority using nice -20 for each of the parallel processes.

The image below show that all the processes are running in nice -20 but each core occupancy is well below 20%.

Is there a way to increase the job performance in a way that the cores are used more efficiently?

Best,
Camps