U.S. Department of EnergyOffice of Scientific and Technical Information
A ghost cell expansion method for reducing communications in solving PDE problems
Abstract
In solving Partial Differential Equations, such as the Barotropic equations in ocean models, on Distributed Memory Computers, finite difference methods are commonly used. Most often, processor subdomain boundaries must be updated at each time step. This boundary update process involves many messages of small sizes, therefore large communication overhead. Here we propose a new approach which expands the ghost cell layers and thus updates boundaries much less frequently ---reducing total message volume and grouping small messages into bigger ones. Together with a technique for eliminating diagonal communications, the method speedup communication substantially, up to 170%. We explain the method and implementation in details, provide systematic timing results and performance analysis on Cray T3E and IBM SP.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE Director, Office of Science. Office of Biological and Environmental Research (US)
- OSTI Identifier:
- 783770
- Report Number(s):
- LBNL-47929
R&D Project: K11501; TRN: AH200128%%204
- DOE Contract Number:
- AC03-76SF00098
- Resource Type:
- Conference
- Resource Relation:
- Conference: Supercomputing 2001 (SC2001), Denver, CO (US), 11/10/2001--11/16/2001; Other Information: PBD: 1 May 2001
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; DATA TRANSMISSION; SUPERCOMPUTERS; FINITE DIFFERENCE METHOD; IMPLEMENTATION; PARTIAL DIFFERENTIAL EQUATIONS; PERFORMANCE; OCEANIC CIRCULATION; GENERAL CIRCULATION MODELS; HIGH PERFORMANCE COMPUTING PARTICIAL DIFFERENTIAL EQUATION
Citation Formats
Ding, Chris H.Q., and He, Yun. A ghost cell expansion method for reducing communications in solving PDE problems. United States: N. p., 2001.
Web.
Ding, Chris H.Q., & He, Yun. A ghost cell expansion method for reducing communications in solving PDE problems. United States.
Ding, Chris H.Q., and He, Yun. 2001.
"A ghost cell expansion method for reducing communications in solving PDE problems". United States. https://www.osti.gov/servlets/purl/783770.
@article{osti_783770,
title = {A ghost cell expansion method for reducing communications in solving PDE problems},
author = {Ding, Chris H.Q. and He, Yun},
abstractNote = {In solving Partial Differential Equations, such as the Barotropic equations in ocean models, on Distributed Memory Computers, finite difference methods are commonly used. Most often, processor subdomain boundaries must be updated at each time step. This boundary update process involves many messages of small sizes, therefore large communication overhead. Here we propose a new approach which expands the ghost cell layers and thus updates boundaries much less frequently ---reducing total message volume and grouping small messages into bigger ones. Together with a technique for eliminating diagonal communications, the method speedup communication substantially, up to 170%. We explain the method and implementation in details, provide systematic timing results and performance analysis on Cray T3E and IBM SP.},
doi = {},
url = {https://www.osti.gov/biblio/783770},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2001},
month = {Tue May 01 00:00:00 EDT 2001}
}