Message passing vs. shared address space on a cluster of SMPs

Conference · Mon Jan 22 04:00:00 EST 2001

OSTI ID:787126

Shan, Hongzhang ^[1]; Singh, Jaswinder Pal; Oliker, Leonid; Biswas, Rupak

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1. LBNL Library

The emergence of scalable computer architectures using clusters of PCs or PC-SMPs with commodity networking has made them attractive platforms for high-end scientific computing. Currently, message passing (MP) and shared address space (SAS) are the two leading programming paradigms for these systems. MP has been standardized with MPI, and is the most common and mature parallel programming approach. However, MP code development can be extremely difficult, especially for irregularly structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality and high protocol overhead. In this paper, they compare the performance of and programming effort required for six applications under both programming models on a 32-CPU PC-SMP cluster. Our application suite consists of codes that typically do not exhibit scalable performance under shared-memory programming due to their high communication-to-computation ratios and complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of the applications; however, on certain classes of problems, SAS performance is competitive with MPI.

• Research Organization: Lawrence Berkeley National Lab., CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of Advanced Scientific Computing Research. Mathematical, Information, and Computational Sciences Division (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 787126
• Report Number(s): LBNL--47806
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
COMPUTER ARCHITECTURE
DATA TRANSMISSION
EFFICIENCY
PARALLEL PROCESSING
PERFORMANCE
PROGRAMMING