How to resolve a parallel solution not using all of the requested CPUs in the same run.

Mel
Mel Altair Community Member
edited September 11 in Altair HyperWorks

On some multi-CPU Windows systems it could happen in some cases that not all of the CPUs (cores) are used by Feko in a parallel run. This could be observed even though the machines file and number of requested processes (cores) specify that all available cores should be used. 
For example, on a machine with 4 CPUs and 32 cores each, it could be observed that no more than 64 cores are used even though a total of 128 processes (cores) where requested.

In cases such as the above, perform the following steps:

  1. Set-up Feko to use MS-MPI. 
  2. Set the environment variable MPIEXEC_AFFINITY=2
  3. Also set the environment variable MPIEXEC_AFFINITY_AUTO=1
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