A High-Performance Design for Hierarchical Parallelism in the QMCPACK Monte Carlo code

Conference · Tue Nov 01 04:00:00 EDT 2022

DOI:https://doi.org/10.1109/HiPar56574.2022.00008· OSTI ID:1963152

Luo, Ye ^[1]; Doak, Peter W. ^[2]; Kent, Paul ^[2]

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1. Argonne National Laboratory
2. ORNL

We introduce a new high-performance design for parallelism within the Quantum Monte Carlo code QMCPACK. We demonstrate that the new design is better able to exploit the hierarchical parallelism of heterogeneous architectures compared to the previous GPU implementation. The new version is able to achieve higher GPU occupancy via the new concept of crowds of Monte Carlo walkers, and by enabling more host CPU threads to effectively offload to the GPU. The higher performance is expected to be achieved independent of the underlying hardware, significantly improving developer productivity and reducing code maintenance costs. Scientific productivity is also improved with full support for fallback to CPU execution when GPU implementations are not available or CPU execution is more optimal.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1963152
• Country of Publication: United States
• Language: English