SCIENCE

This month, the NASA Center for Climate Simulation (NCCS) made available to users the newest unit of its "Discover" supercomputer. The 14,400-processor Dell PowerEdge C6100 server doubles Discover's computational power to more than 320 trillion floating-point operations per second (teraflops) peak.

"Our vendor partners Dell, Intel, Mellanox, Coolcentric, and Force10 went the extra mile in building an innovative computing system that equals all of Discover's previous resources but uses less than 40 percent of the space and only 45 percent of the electricity," said Phil Webster, NCCS project manager and chief of the Computational and Information Sciences and Technology Office at NASA Goddard Space Flight Center. "The expanded capabilities are supporting NASA contributions to international climate science programs as well as advancing the state-of-the-art in modeling and simulation."

The PowerEdge C6100 uses current-generation Intel Xeon 5600 "Westmere" (2.8 GHz) processor technology and offers 28.8 terabytes of memory. Its 40 gigabit-per-second InfiniBand network enables the fastest inter-processor communication on Discover, a trait particularly useful for climate simulation with its frequent passing of information among computational grid points.

Offering more than three times the performance of any other unit on Discover, this newest unit represents the largest single expansion of the supercomputer. The unit has already demonstrated a reduction in turnaround times for the heavily used computing system. Since 2008, NCCS has quadrupled Discover's performance to support NASA Science Mission Directorate high-end computing needs.

Through at least July 1, 2011, NCCS is reserving 8,640 processors of the new unit for "large-scale research runs, those using 1,000 processors or more at a time," said Dan Duffy, NCCS lead architect. "Our users have an opportunity to see how well their software codes can profit from thousands of processors, both in terms of faster time to solution and increased science capabilities. After July 1, we will evaluate and either keep these processors for large runs or open them up to general use."

Harnessing a significant portion of the unit's remaining 5,760 processors and other Discover resources, the Global Modeling and Assimilation Office (GMAO) and the Goddard Institute for Space Studies (GISS) are busy running simulations for the Fifth Assessment Report of the International Panel on Climate Change (IPCC) and the Coupled Model Intercomparison Project Phase 5 (CMIP5). Using a variety of modeling techniques and resolutions, NASA simulations will collectively span the years 1000 through 2100. Data from these simulations will be available to the climate science community on the NCCS node of the Earth System Grid.

With the large-scale research partition GMAO researchers are moving towards the next version of the Goddard Earth Observing System (GEOS) Model, GEOS-6. Efforts include extending the duration of 3.5-kilometer-resolution (and eventually finer-resolution) global simulations, employing updated model physics to explore the role of atmospheric convection in adverse weather events, and coupling the Goddard Chemistry Aerosol Radiation and Transport (GOCART) Model for aerosol-weather interactions and observing system science for future NASA missions.