期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2011
卷号：3
期号：4
页码：1-22
DOI：10.1029/2011MS000073
出版社：John Wiley & Sons, Ltd.
摘要：We present an analysis of the performance aspects of an atmospheric general circulation model at the ultra‐high resolution required to resolve individual cloud systems and describe alternative technological paths to realize the integration of such a model in the relatively near future. Due to a superlinear scaling of the computational burden dictated by the Courant stability criterion, the solution of the equations of motion dominate the calculation at these ultra‐high resolutions. From this extrapolation, it is estimated that a credible kilometer scale atmospheric model would require a sustained computational rate of at least 28 Petaflop/s to provide scientifically useful climate simulations. Our design study portends an alternate strategy for practical power‐efficient implementations of next‐generation ultra‐scale systems. We demonstrate that hardware/software co‐design of low‐power embedded processor technology could be exploited to design a custom machine tailored to ultra‐high resolution climate model specifications at relatively affordable cost and power considerations. A strawman machine design is presented consisting of in excess of 20 million processing elements that effectively exploits forthcoming many‐core chips. The system pushes the limits of domain decomposition to increase explicit parallelism, and suggests that functional partitioning of sub‐components of the climate code (much like the coarse‐grained partitioning of computation between the atmospheric, ocean, land, and ice components of current coupled models) may be necessary for future performance scaling.
关键词：global cloud system resolving models;exascale computing;hardware/software co‐design
