A view of one of the aisles of racks that hold Sequoia’s 1.6 million cores. Its 16.32 sustained petaflops and 1.6 petabytes of memory make it the world's fastest supercomputer. | Photo courtesy of Lawrence Livermore National Laboratory.


Last week, the TOP500 list, the biannual ranking of the fastest supercomputers in the world came out with Energy Department machines occupying three of the top 10 places – including the top spot.

The list released June 18 at the International Supercomputing Conference in Hamburg, Germany, ranked Sequoia at Lawrence Livermore National Laboratory as the world’s most powerful supercomputer. Mira at Argonne National Laboratory in Argonne, Illinois, ranked third; and Jaguar at Oak Ridge National Laboratory ranked sixth.

Clocking in at 16.32 sustained petaflops, Sequoia is now the fastest supercomputer on the planet. Capable of running 16,000 trillion calculations per second, the IBM Blue Gene/Q system will be dedicated to the NNSA’s Advanced Simulation and Simulation program to assess the condition and reliability of the nuclear weapon stockpile without having to perform detonation tests. The computer’s 1.6 million cores and 1.6 petabytes of memory will significantly reduce the time it takes to perform these tests and also provide a previously unattainable level of clarity in the simulations.  

Mira, Argonne National Lab’s new IBM Blue Gene/Q system uses 786,432 processing cores on 48 racks to achieve a processing power of 10 petaflops. The system ranks as the third most powerful computer in the world, and, rather than a dedicated purpose, it’s open to any researcher selected by proposal. Located at the Argonne Leadership Computing Facility (ALCF), Mira will provide billions of processor-hours each year to accelerate research in the areas of physics, chemistry, and engineering. One team of physicists will be running high-resolution simulations of the distribution of matter. Another team will be running calculations to identify new materials for energy storage.

In sixth place worldwide, and third in the United States, was Jaguar – the petascale supercomputer that powers the Virtual Environment for Reactor Applications (VERA), which allows engineers building new nuclear reactors to simulate coolant flow, fuel performance, and other difficult-to-observe functions. Jaguar currently runs at 2.3 petaflops, which made it the top supercomputer on the planet for about a year. Jaguar is currently being phased out to make way for Titan, its 20-petaflop successor.

The National Labs have a long history of building and using superior computing power for research across disciplines. Just four years ago, Los Alamos’ Roadrunner supercomputer was the first system to break the petaflop barrier – a significant and long-awaited step in computing. And even as supercomputers rise and fall on the TOP500 list, researchers are making their way to the next big challenge, the exascale, which would be able to model the impact of wind and tidal effects on superstructures of off-shore wind turbines, or more precisely predict the weather.  

In the meantime, petascale computing is advancing research in physics, material science, and energy technology in far-reaching ways.