Calculation efficiency

User Support
1

Hi Guys,

I’m running a depletion calculation of a small PWR with 330 MWth on the University High performance computing cluster. Usually, for each calculation, I require 40 core and memory per CPU as 4096 MB. However, the output file present the calculation rate (inactive) = 1261.07 particles/second, calculation Rate (active) = 644.439 particles/second. On my laptop, the calculation Rate (inactive) = 30976.0 particles/second and calculation Rate (active) = 30298.8 particles/second. The calculation rates on HPC are lower than that on my laptop.

Does anyone know what’s going on? And how to accelerate the calculation? I tried to call the OpenMPI with calculation but that lead to the ‘bus error’ many times. Therefore, I think I should try to extend OpenMP threads, but how to set the number of thread?

Thanks,
Yiming

2

@YimingZ I’d suggest reading through the user’s manual section on running in parallel. If you’re running from the Python API, you can set the number of threads with:

openmc.run(threads=...)

From the command line, you can use the -s command-line argument. However, note that the default behavior is to use OpenMP and to use as many threads as there are cores available on a system.