The high-resolution direct numerical simulations (DNSs) of incompressible turbulence with numbers of grid points up to 40963 have been executed on the Earth Simulator (ES). The DNSs are based on the Fourier spectral method, so that the equation for mass conservation is accurately solved. In DNS based on the spectral method, most of the computation time is consumed in calculating the three-dimensional (3D) Fast Fourier Transform (FFT), which requires huge-scale global data transfer and has been the major stumbling block that has prevented truly high-performance computing. By implementing new methods to efficiently perform the 3D-FFT on the ES, we have achieved DNS at 16.4 Tflops on 20483 grid points. The DNS yields an energy spectrum exhibiting a wide inertial subrange, in contrast to previous DNSs with lower resolutions, and therefore provides valuable data for the study of the universal features of turbulence at large Reynolds number.

Article Free Access Share on An I/O network architecture of the distributed shared-memory massively parallel computer JUMP-1 Authors: Hironori Nakajo Department of Computer and Systems Engineering, Kobe University Department of Computer and Systems Engineering, Kobe UniversityView Profile , Satoshi Ohtani Department of Computer and Systems Engineering, Kobe University Department of Computer and Systems Engineering, Kobe UniversityView Profile , Takashi Matsumoto Department of Information Science, The University of Tokyo Department of Information Science, The University of TokyoView Profile , Masadi Kohata Department of Information and Computer Engineering, Okayama University of Science Department of Information and Computer Engineering, Okayama University of ScienceView Profile , Kei Hiraki Department of Information Science, The University of Tokyo Department of Information Science, The University of TokyoView Profile , Yukio Kaneda Department of Computer and Systems Engineering, Kobe University Department of Computer and Systems Engineering, Kobe UniversityView Profile Authors Info & Claims ICS '97: Proceedings of the 11th international conference on SupercomputingJuly 1997 Pages 253–260https://doi.org/10.1145/263580.263645Published:11 July 1997Publication History 4citation247DownloadsMetricsTotal Citations4Total Downloads247Last 12 Months2Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

JUMP-1 is a distributed shared-memory massively parallel computer and is composed of multiple clusters of inter-connected network called RDT (Recursive Diagonal Torus). Each cluster in JUMP-1 consists of 4 element processors, secondary cache memories, and 2 MBP (Memory Based Processor) for high-speed synchronization and communication among clusters. The I/O subsystem is connected to a cluster via a high-speed serial link called STAFF-Link. The I/O buffer memory is mapped onto the JUMP-1 global shared-memory to permit each I/O access operation as memory access. In this paper we describe evaluation of the fundamental performance of the disk I/O subsystem using event-driven simulation, and estimated performance with a Video On Demand (VOD) application.

We developed a parallel processing system for analyzing phylogenetic relationships of microorganisms based on a maximum likelihood method. Methods for inferring relationships from molecular sequence data are especially valuable, given the enormous increases in DNA sequence data. The maximum likelihood method uses concrete models of the evolutionary process and are well-motivated statistically, but the computational cost has hindered the use of this method for inferring trees with more than about 20 organisms. We parallelized the maximum likelihood method by utilizing two types of parallelism, parallel evaluation of phylogenetic trees and parallel computation of likelihood values. By combining these two parallelisms, we obtained significant speedup on the Intel Touchstone DELTA.