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Title: Experiences in the Performance Analysis and Optimization of a Deterministic Radiation Transport Code on the Cray SV1

Conference ·
OSTI ID:910811

The Attila radiation transport code, which solves the Boltzmann neutron transport equation on three-dimensional unstructured tetrahedral meshes, was ported to a Cray SV1. Cray's performance analysis tools pointed to two subroutines that together accounted for 80%-90% of the total CPU time. Source code modifications were performed to enable vectorization of the most significant loops, to correct unfavorable strides through memory, and to replace a conjugate gradient solver subroutine with a call to the Cray Scientific Library. These optimizations resulted in a speedup of 7.79 for the INEEL's largest ATR model. Parallel scalability of the OpenMP version of the code is also discussed, and timing results are given for other non-vector platforms.

Research Organization:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
DE-AC07-99ID-13727
OSTI ID:
910811
Report Number(s):
INEEL/CON-04-01971; TRN: US200802%%188
Resource Relation:
Conference: Cray User Group Meeting,Knoxville, TN,05/17/2004,05/21/2004
Country of Publication:
United States
Language:
English