Pleiades – NASA’s “Deep Thought”

NASA-ares-1_540x415"Good morning, Dave." NASA uses "Pleiades," its petaflops supercomputer, to make blindingly fast and accurate measurements in the field of “higher fidelity” modeling and simulation. For instance, NASA already is using supercomputers to model black holes. It will also help NASA to design and develop such things as hypersonic airacraft and spacesuits, and simulate the landing of spacecraft on various celestial bodies such as the Moon, Mars, Titan, and asteroids. NASA's newest supercomputer at Ames Research Center, Moffett Field, Calif., has garnered the number six spot on the Top 500 list of the world's most powerful computers. 

The Pleiades supercomputer is an SGI® Altix® ICE system with 12,800 Intel® Xeon® quad-core processors (51,200 cores, 100 racks) running at 487 trillion floating point operations per second (teraflops) on the LINPACK benchmark, the industry standard for measuring a system's floating point computing power. One of the most powerful general-purpose supercomputers ever built, Pleiades also features the world's largest InfiniBand® interconnect network. 

The LINPACK run also measured electrical power consumption—an increasingly important consideration in high-end computing. Using a total of 2.09 megawatts, or 233 megaflops per watt, Pleiades is among the most energy-efficient supercomputers in the world. 

"Pleiades represents a significant engineering achievement in several ways," said William Thigpen, Pleiades project manager at the NASA Advanced Supercomputing (NAS) Division at Ames. In addition to its power and InfiniBand record, "Pleiades can run NASA codes with minimal modifications, and is compatible with standard desktop engineering workstations so our users can migrate codes easily from their desktops. Users from all key mission areas will have an enormous resource to meet their critical milestones," Thigpen added. 

Among the scientific and engineering projects accepted for computer time on Pleiades are:

Extensive simulations of large computational problems for future space vehicle design; Development of increasingly detailed models of large-scale dark matter halos and galaxy evolution; Running coupled atmosphere-ocean models to assess decadal climate prediction skill for the Intergovernmental Panel on Climate Change.

Pleiades was acquired to augment the space agency's Columbia supercomputer (ranked No. 2 on the Top500 list in November 2004) in supporting NASA's four key mission areas: aeronautics research, exploration systems, science, and space operations. 

Pleiades is used by NASA personnel across the agency for research in earth and space sciences, and for conducting giant simulations. The machine is almost fully subscribed–meaning that it is in use 24 hours a day, seven days a week.

Inside the computing center, the agency maintains rack after rack of the SGI machines that make up Pleiades, most of which have 512 cores, or about 6 teraflops. But recently, the center added 32 new racks with 768 cores–some of which are seen here.

Things move fast in the world of supercomputers. When Pleiades was debuted in November 2008, it was measured at 487 teraflops and was the third-most powerful computer. Now, almost a year and a half later, although it has dropped to sixth place on the list, it has doubled its power.

The image above created with Pleiades that shows a visualization of the Ares-1's main engine plume interacting during a type-4 stage separation with the Interstage. To better depict the lower Mach numbers and the flowfield overall, the Mach contours are shown on a logarithmic scale.

Casey Kazan via NASA

Photo by Goetz Klopfer, NASA Exploration Systems MissionDirectorate

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