A Micro-Benchmark Evaluation of Catamount and Cray Linux Environment (CLE) Performance

A Micro-Benchmark Evaluation of Catamount and Cray Linux Environment (CLE) Performance Jeff Larkin, Cray Inc. Jeffery A. Kuehn, Oak Ridge National Laboratory ABSTRACT: Over the course of 2007 Cray has put significant effort into optimizing the Linux kernel for large-scale supercomputers. Many sites have already replaced Catamount on their XT3/XT4 systems and many more will likely make the transition in 2008. In this paper we will present results from several micro-benchmarks, including HPCC and IMB, to categorize the performance differences between Catamount and CLE. The purpose of this paper is to provide users and developers a better understanding of the effect migrating from Catamount to CLE will have on their applications. KEYWORDS: Catamount, Linux, CLE, CNL, HPCC, Benchmark, Cray XT by the differences between Catamount and CLE. We will 1. Introduction briefly discuss each operating system and the benchmark Since the release of the Cray XT series methodology used. Next we will present the results of [3,4,5,6,7,18,19] of MPP systems, Cray has touted the several benchmarks and highlight differences between the extreme scalability of the light-weight Catamount two operating systems. Finally we will conclude with an operating system from Sandia National Laboratory. To interpretation of how these results will affect application achieve its scalability, Catamount sacrificed some performance. functionality generally found in more general purpose ...