NCSHMEM: Difference between revisions

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{{TAGDEF|NCSHMEM|[integer]|1 }}
{{TAGDEF|NCSHMEM|[integer]|1 }}


Description: {{TAG|NCSHMEM}} determines the number of compute cores sharing the memory (shared memory MPI) in the old GW routines.
Description: {{TAG|NCSHMEM}} determines the number of compute cores sharing the memory in MPI in the non-cubic scaling GW routines.


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By default no shared memory MPI is in the non-cubic scaling GW routines ({{TAG|ALGO}}=EVGW, EVGW0, QPGW and QPGW0).
For using shared memory MPI in the non-cubic scaling GW set NCSHMEM=-1.
{{NB|warning|For the openmp version NCHSMEM is not active and shared memory is not used for MPI. In that case the memory is shared between threads.}}
== Related tags and articles ==
== Related tags and articles ==
[[Shared memory]]
[[Shared memory]], {{TAG|ALGO}}, [[Practical guide to GW calculations]]


[[Category:Performance]][[Category:VASP6]][[Category:Machine-learned force fields]][[Category:Memory]]
[[Category:Performance]][[Category:Many-body perturbation theory]][[Category:GW]][[Category:Memory]]

Latest revision as of 09:38, 21 July 2022

NCSHMEM = [integer]
Default: NCSHMEM = 1 

Description: NCSHMEM determines the number of compute cores sharing the memory in MPI in the non-cubic scaling GW routines.


By default no shared memory MPI is in the non-cubic scaling GW routines (ALGO=EVGW, EVGW0, QPGW and QPGW0). For using shared memory MPI in the non-cubic scaling GW set NCSHMEM=-1.

Warning: For the openmp version NCHSMEM is not active and shared memory is not used for MPI. In that case the memory is shared between threads.

Related tags and articles

Shared memory, ALGO, Practical guide to GW calculations