In October, the U.S. National Nuclear Security Administration officially dedicated two state-of-the-art supercomputers that should allow the United States' nuclear weapons arsenal to be kept in working order without the need for underground testing. One of those is now the fastest computer ever built.

PHOTO: National Nuclear Security Administration/Nevada Site Office

VENTING: This 1970 underground test released radioactivity into the atmosphere above the Nevada desert.

According to the NNSA, a new IBM BlueGene/L and an IBM Purple system have been successfully installed and tested at the recently completed Terascale Simulation Facility at Lawrence Livermore National Laboratory, in California. Nuclear scientists will use the two supermachines to run three-dimensional simulations at dizzying speeds to achieve much of the nuclear weapons analysis that was formerly accomplished by underground nuclear testing, capping a long campaign to use virtual testing in place of physical weapons detonations.

"The unprecedented computing power of these two supercomputers is more critical than ever to meet the time-urgent issues related to maintaining our nation's aging nuclear stockpile without testing," said NNSA Administrator Linton F. Brooks. "Purple represents the culmination of a successful decade-long effort to create a powerful new class of supercomputers. BlueGene/L points the way to the future and the computing power we will need to improve our ability to predict the behavior of the stockpile as it continues to age."

Brooks announced on 27 October that the BlueGene/L had performed a record 280.6 trillion floating-point operations per second on the industry standard Linpack benchmark test suite. The Linpack test is used to determine the performance of the world's fastest computers, which are ranked in the routinely updated Top 500 list. The new record doubles the previous top performance, achieved in March by an earlier configuration of this same Livermore BlueGene/L system.

This computing advance is a significant accomplishment. It should improve the prospects of the United States' agreeing to permanently stop physical nuclear weapons testing, under the Comprehensive Nuclear Test Ban Treaty, which was concluded in 1996. And on a related front, the award of this year's Nobel Peace Prize to the Vienna-based International Atomic Energy Agency and its director general, Mohamed ElBaradei [see William Sweet's news commentary "The Atomic Energy Agency's Peace Prize"] is a victory for the defenders of the Nuclear Non-Proliferation Treaty. Taken together, virtual testing technology and the reaffirmation of the importance of nuclear arms control promise to make the real world a safer place.