World’s Fastest Supercomputers Open to Academia

Crunching numbers to check the design and reliability of nuclear weapons is the main job of BlueGene/L and ASC Purple, but the two supercomputers in Lawrence Livermore National Laboratory’s new Terascale Simulation Facility are also available roughly 12% of the time for nonclassified research.

“The new machines are creating simulations at unprecedented detail and speed,” says Dona Crawford, LLNL associate director for computation. BlueGene/L, which for the last year has held the record as the world’s most powerful computer, and ASC Purple are used for different aspects of the US Department of Energy’s nuclear weapons stockpile stewardship program. “Had we attempted to procure a single computer capable of solving all our computational problems rather than utilizing two machines, the cost would have been double the $200 million we spent,” Crawford says.

ASC Purple can simulate, in three dimensions and in a single data run, both the primary fission explosion and the secondary fusion explosion of a nuclear weapon. BlueGene/L has been honed for studies of molecular dynamics, dislocation dynamics in metals, and grain-scale chemical re-actions in high explosives, allowing scientists to better understand the behavior of aged material in weapons systems. Both supercomputers will also simulate, among other things, aspects of test shots for LLNL’s National Ignition Facility and the effect weather conditions have on the dispersal of biological agents.

Livermore broke ground on the new computer facility three years ago and began moving staff and equipment into it earlier this year. The 23 500-square-meter building uses enough power to heat more than 12 000 homes. The 100-teraflop ASC Purple, which came online in October, contains 12 208 processors, 4 gigabytes of random-access memory per processor, and 2 petabytes of disk space. The 136.8-Tflop BlueGene/L was recently upgraded to 131 072 processors, 256 megabytes of ram per processor, and 2 terabytes of disk space.

Academic researchers from five institutions have already started using the machines during the shakedown phase before classified research becomes dominant in early 2006. Indeed, the Terascale Simulation Facility’s biggest problem may be its popularity, says Crawford: “We’re already oversubscribed by a factor of four by requests to use the machines.”