MPAS | Scalability | Speedup

• WRF | MPAS | MPI | halo/ghost cell
• MPAS | -fp-model precise
  • Speedup

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Introduction

• Speedup tells you how much faster your parallel algorithm can be than its sequential counterpart.
• Scalability tells you how the performance of your parallel algorithm behaves as you add hardware.

Experiment (no precise mode)

• MPASv8.2.2 by intel compiler
• MPAS-120km: x1.40962
• Core = 2, 4, 8, 16, 24, 32, 48, 68, 68xN
• Initial datetime = 2023-04-02_00UTC
• IC source = ERA5
• T+12days

Elapsed time

Step	Mesh	IC	Elapsed time	Core
init	MPAS-120km-MPASv822	2023040200	<60s	68
atm	MPAS-120km-MPASv822	2023040200	1h20m	68x4
atm	MPAS-120km-MPASv822	2023040200	1h33m	68x3
atm	MPAS-120km-MPASv822	2023040200	2h5m	68x2
atm	MPAS-120km-MPASv822	2023040200	2h8m	68
atm	MPAS-120km-MPASv822	2023040200	3h30m	48
atm	MPAS-120km-MPASv822	2023040200	4h51m	32
atm	MPAS-120km-MPASv822	2023040200	9h24m	24
atm	MPAS-120km-MPASv822	2023040200	16h50m	16
atm	MPAS-120km-MPASv822	2023040200	25h33m	8
atm	MPAS-120km-MPASv822	2023040200	49h20m	4
atm	MPAS-120km-MPASv822	2023040200	62h36m	2

• Averaging t2m globally

References

1. Towards convection-resolving, global atmospheric simulations with the Model for Prediction Across Scales (MPAS): an extreme scaling experiment
2. X. Hao et al., "swMPAS-A: Scaling MPAS-A to 39 Million Heterogeneous Cores on the New Generation Sunway Supercomputer," in IEEE Transactions on Parallel and Distributed Systems, vol. 34, no. 1, pp. 141-153, 1 Jan. 2023, doi: 10.1109/TPDS.2022.3215002. keywords: {Atmospheric modeling;Computational modeling;Supercomputers;Predictive models;Task analysis;Computer architecture;Scalability;MPAS-A;atmosphere science;heterogeneous core;sunway supercomputer;I/O},