Author(s)

P. N. Brown, B. Chang, U. R. Hanebutte and C. S. Woodward

Abstract

The quest for a high performance Boltzmann transport solver P. N. Brown, B. Chang, U. R. Hanebutte & C. S. Woodward Center/or Applied Scientific Computing, Lawrence Livermore National Laboratory, USA. Abstract A 3-d Boltzmann transport code developed at Lawrence Livermore National Laboratory exploits concurrency (problem permitting) with respect to all phase space variables represented by direction, position and energy. To demonstrate the capabilities of the code, a highly resolved Boltzmann transport calculation with 27.6 billion unknowns (332 billion discretization points) was performed on 4992 processors of the IBM RS/6000 SP ASCI Blue machine at Lawrence Livermore National Laboratory. Detailed performance measurements were collected during this calculation. Analyzing the timing data revealed a relatively modest performance, i.e. obtained fraction of peak performance. A detailed study of the performance data confirmed that this modest performance was caused by low utiliz

Keywords