[Parisa_Khiabani]

Hi everyone,
I am using OpenFOAM 2.1.1.
I am wondering if I can run the cases in multi cores? My machine has 2 CPUs, each include 12 cores.
I really appreciate your support,

Parisa

[Lieven]

Hi Parisa,

Briefly said, you need to decompose your case using the 'decomposePar' utility and start the job with e.g. (adjust the solver name to your own preference)

foamJob -p simpleFoam

Afterwards, you can reconstruct the solution with 'reconstructPar'. Have a look at the dambreak tutorial if you want to have an example:
http://www.openfoam.org/docs/user/da...hp#x7-500002.3

Cheers,

Lieven

[Parisa_Khiabani]

Thanks for your help,
In the tutorial, it is decomposed for several CPUs. But I would lke to run in different cores. Is there any difference?

[Lieven]

There is no difference, since you select the number of processors. Using your terminlogoly:
you have 24 processors in total (2x12). You can select any number of processors between 1 and 23 to do the calculations. OpenFOAM will divide the work over the difference CPUs and cores automatically. But always test if your simulation effectively runs faster when increasing the number of cores. So don't blindly jump to 23 processors, test with 4, 8, 16 or so and check if the computation time decreases with increasing number of procs.

Just as a note, you shouldn't select all 24 processors since you need one for the operating system.

Cheers,

L

[Z.Q. Niu]

Hi Lieven,
Do you know how to run reconstructPar in parallel?

[Lieven]

Hi Z.Q. Niu,

As far as I know this is not possible...