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Title: Vectorizing the Community Land Model (CLM)

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.

Authors:
 [1];  [2];  [3];  [1]
  1. ORNL
  2. National Center for Atmospheric Research (NCAR)
  3. Central Research Institute of Electric Power Industry, Japan
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Sciences (NCCS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1003247
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Journal Name:
International Journal of High Performance Computing Applications
Additional Journal Information:
Journal Volume: 19; Journal Issue: 3; Journal ID: ISSN 1094--3420
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; 54 ENVIRONMENTAL SCIENCES; CLIMATES; PERFORMANCE; SIMULATORS; VECTORS

Citation Formats

Hoffman, Forrest M, Vertenstein, Mariana, Kitabata, Hideyuki, and White, III, James B. Vectorizing the Community Land Model (CLM). United States: N. p., 2005. Web. doi:10.1177/1094342005056113.
Hoffman, Forrest M, Vertenstein, Mariana, Kitabata, Hideyuki, & White, III, James B. Vectorizing the Community Land Model (CLM). United States. https://doi.org/10.1177/1094342005056113
Hoffman, Forrest M, Vertenstein, Mariana, Kitabata, Hideyuki, and White, III, James B. 2005. "Vectorizing the Community Land Model (CLM)". United States. https://doi.org/10.1177/1094342005056113.
@article{osti_1003247,
title = {Vectorizing the Community Land Model (CLM)},
author = {Hoffman, Forrest M and Vertenstein, Mariana and Kitabata, Hideyuki and White, III, James B},
abstractNote = {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.},
doi = {10.1177/1094342005056113},
url = {https://www.osti.gov/biblio/1003247}, journal = {International Journal of High Performance Computing Applications},
issn = {1094--3420},
number = 3,
volume = 19,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2005},
month = {Sat Jan 01 00:00:00 EST 2005}
}