Seminario COMPUTATIONAL FLUID DYNAMICS (CFD) ON MACHINES WITH HUNDREDS OF THOUSAND OF CORES por Rainald Lohner
Martes 12 de Junio de 2012 a las 12.30
Seminario 1. Planta 4. ETSICCP. UGR.
(Escuela de Caminos, Campus Fuentenueva)
Rainald Lohner PhD, DSc
Distinguished Professor of Fluid Dynamics
School of Computational Sciences
George Mason University
Fairfax, VA, USA. www.scs.gmu.edu/~rlohner
SUMMARY
The recent availability of machines with hundreds of thousands of cores has led to a renewed interest in porting and scaling to this level of parallelism. In the first part of the talk, several of these developments will be highlighted.
Thereafter, the consequences that the recent stagnation in clockrates for CPUs has had on large-scale CFD runs are examined. At first sight, the conclusion is that only massive parallelism at the loop or domain decomposition level will lead to higher FLOP counts. However, the significant differences in advances for CPUs/GPUs versus RAM and interprocessor communication bandwidth lead to a so-called ‘limiting domain size’, below which communication dominates execution times and performance degrades drastically.
The consequences of this `red-shift’ for the future of CFD are manifold: the time to advance the solution one timestep is limited, implying that even with unlimited number of processors/cores, LES, DES and DNS runs for realistic Reynolds-numbers will require days or weeks of execution.Examples from daily production runs reaching 50,000 cores will be shown.
Para más información, contactar con el Coordinador del Programa,
Dr. Pablo Ortiz
Prof. Tit. Ing. Hidraulica. Univ. de Granada
Edif. Polit., Campus Fuentenueva. 18071. Granada, Spain.
Tel: 34-958-249436. Fax: 34-958-249959, portiz@ugr.es
