How to choose number of CPU Cores

salehmeiabadi · February 2021

Hi there

We have 8 cores on a node in our Linux machine and DualSPHysics uses all 8 cores to run a simulation.

What if I want to use for example 4 cores or 2 cores?

How can I set the number of cores which will be used by machine?

Thanks a lot for any help.

Asalih3d · February 2021

Hi

Look at:

help\DualSPHysics5.0_Help.out

And its specified entry, "-ompthreads":

    -ompthreads:<int>  Only for CPU execution, indicates the number of threads
                   by host for parallel execution, this takes the number of 
                   cores of the device by default (or using zero value)

Kind regards

salehmeiabadi · February 2021

Thanks alot

salehmeiabadi · February 2021

Thank you so much for your response.

I could not find -ompthreads in the execution parameters in Case_Def.xml file.

Could you please let me know where I should specify number of threads?

King regards

Alex · February 2021

That is only available in the command line, not in the XML

Regards

salehmeiabadi · March 2021

Hello

I just wanted to share my finding on how to request a number of cores for a job using SBATCH on a cluster.

When submitting a job you can request the number of cores by a simple script like this:

#!/bin/bash

#SBATCH --account= ----------------

#SBATCH --time=00:60:00

#SBATCH --cpus-per-task=36

export OMP_NUM_THREADS=$SLURM_CPUS_PER_TASK

cd /home/saleh85/DualSPHysics_v5.0/examples/mphase_nnewtonian/02_Poiseuille

./xCasePoiseuilleNN_linux64_CPU.sh

Here I requested 36 cores.

Good luck

How to choose number of CPU Cores

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