pygsti.tools.mpitools.compute_blas_threads

compute_blas_threads(num_ranks, blas_threads_per_rank)

Return the number of BLAS threads that should be assigned to each MPI rank on the current node, assuming num_ranks in total.

Parameters:

• num_ranks (int) – Total number of MPI ranks launched on this node.

• blas_threads_per_rank (int) – Desired thread count. When non-zero, returned as-is. When 0, the value is auto-detected as max(1, num_physical_cpus // num_ranks).

Returns:

Thread count per rank (always >= 1).

Return type:

int

Notes

Auto-detection uses psutil.cpu_count(logical=False)() when psutil is available, falling back to os.cpu_count(). The result is measured on the machine where this function is called, which may differ from remote HPC compute nodes. Pass an explicit blas_threads_per_rank when targeting a different machine.