SC Conference - Activity Details

Simulation of Compressible Fluid Flow on Roadrunner

Jamaludin Mohd-Yusof  (Los Alamos National Laboratory)
Daniel Livescu  (Los Alamos National Laboratory)
Timothy M. Kelley  (Los Alamos National Laboratory)
Mark R. Petersen  (Los Alamos National Laboratory)
Nehal Desai  (Los Alamos National Laboratory)
Posters Session
Tuesday,  05:15PM - 07:00PM
Room Rotunda Lobby
We present details of a parallel hybrid implementation of a compressible Navier-Stokes solver on the new petascale supercomputer, Roadrunner. This is the first implementation of a large structured-grid fluid dynamics code on this architecture. In contrast to other applications that have been ported to Roadrunner, codes of this type are typically limited by memory bandwidth. We show that the excellent memory subsystem of the Cell, coupled with explicit memory management, allows an order of magnitude speed improvement compared to Opteron-only versions and effective memory throughput exceeding 50% of theoretical peak. The resulting imbalance between inter-node communication and compute speed required refactoring of key sections of the code. In addition, the dual memory spaces of the hybrid architecture are leveraged to maximize performance and available memory, enabling the largest simulations to date of compressible turbulence. Specific applications targeted by the code include the Rayleigh-Taylor instability and flame propagation in supernovae.
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