Title
Vectorizing the Community Land Model
Abstract
In this paper we describe our extensive efforts to rewrite the Community Land Model (CLM) so that it provides good vector performance on the Earth Simulator in Japan and the Cray X1 at Oak Ridge National Laboratory. We present the technical details of the old and new internal data structures, the required code reorganization, and the resulting performance improvements. We describe and compare the performance and scaling of the final CLM Version 3.0 (CLM3.0) on the IBM Power4, the Earth Simulator, and the Cray X1. At 64 processors, the performance of the model is similar on the IBM Power4, the Earth Simulator, and the Cray X1. However, the Cray X1 offers the best performance of all three platforms tested from 4 to 64 processors when OpenMP is used. Moreover, at low processor counts (16 or fewer), the model performs significantly better on the Cray X1 than on the other platforms. The vectorized version of CLM was publicly released by the National Center for Atmospheric Research as the standalone CLM3.0, as a part of the new Community Atmosphere Model Version 3.0 (CAM3.0), and as a component of the Community Climate System Model Version 3.0 (CCSM3.0) on June 23, 2004.
Year
DOI
Venue
2005
10.1177/1094342005056113
IJHPCA
Keywords
Field
DocType
vectorization,good vector performance,community climate,earth simulator,system model version,best performance,clm,resulting performance improvement,community land model,cray x1,ibm power4,ccsm,final clm version,community cli- mate system model,data structure,community climate system model,mating system
Data structure,IBM,Computer science,Parallel computing,Vectorization (mathematics),Atmospheric model,Oak Ridge National Laboratory,Community Climate System Model,Cray XK7,Operating system,Red Storm
Journal
Volume
Issue
ISSN
19
3
1094-3420
Citations 
PageRank 
References 
3
0.59
0
Authors
4
Name
Order
Citations
PageRank
Forrest M. Hoffman110514.14
Mariana Vertenstein2847.17
Hideyuki Kitabata330.59
James B. White III47915.09