The Energy Department is shutting down Purple, a five-year-old supercomputer that was once the darling of the government's fleet of machines for simulating nuclear weapons performance.
Energy officials announced the department has turned off the IBM machine that was procured for $230 million, following a decade-long pursuit to build a 100 teraflop-per-second computer. A teraflop is 1 trillion computer operations per second. Scientists used Purple to simulate the aging of the nation's nuclear stockpile, without testing nuclear weapons underground.
Taking the system offline is expected to free up personnel, space and money to operate even faster systems, Energy officials said Wednesday night.
When it was unveiled in 2005, Purple and sister computer BlueGene/L -- both housed at the Lawrence Livermore National Laboratory in California -- held more supercomputing power than any other scientific computing facilities on Earth.
"The Purple machine was the icon of the Advanced Simulation and Computing Initiative kicked off in 1996 that was intended to demonstrate that science-based simulations could effectively underwrite the nation's nuclear deterrent during a moratorium on underground nuclear explosive testing," said Don Cook, deputy administrator for defense programs at Energy's National Nuclear Security Administration.
NNSA spokesman Damien LaVera added that since 2005, "thanks in large part to the NNSA's continued investment in supercomputers, platforms have gotten exponentially larger and faster. Purple has served its mission, and been replaced by even more powerful and energy efficient platforms."
Research scientists said it is understandable that, since the agency has an ongoing need to conduct large-scale simulations, it wants to be efficient in its use of people, power and space.
"They want to make sure they are utilizing the best machine that they can put in play," said Stanley C. Ahalt, director of the Renaissance Computing Institute, a collaborative academic center in the Research Triangle area of North Carolina. "The unfortunate situation is that these machines that are very costly become obsolete very quickly. For NNSA, which has such a critical mission in terms of managing the nuclear stockpile they have to refresh the machines. Five years was a good run."
The computer simulations that Purple brought to bear added a third leg of science, alongside theory and experiment, Energy officials noted.
But that third leg needs to be propped up, computing experts say. For more than half a decade, the scientific community has been warning that foreign countries soon will eclipse the United States in supercomputing prowess if the government does not increase funding for equipment and training. The nation relies on the uber-processing speeds of the systems for modeling scenarios ranging from climate change to the spread of a pandemic flu.
"The real problem is that we are not educating the next generation of [Americans] to understand how to use these machines," Ahalt said. "Computational science is a critically important area for our security and for our ability to stay in front of research and development. China is making investments in people who know how to use these things."
Normally U.S. systems dominate the top spots on a half-yearly list of the world's 500 most powerful supercomputers. But, in June, a Chinese supercomputer -- Nebulae -- ranked second for the first time in history, at 1,271 teraflops, and theoretically can perform faster than the No. 1 machine, Energy's 1,759 teraflop Jaguar. Researchers expect that China's system will top the list when it is updated next week.