What Are You Working on Today, Roadrunner?

Over the last week, we managed to get some of the nation’s biggest and baddest supercomputers to take a moment away from their gigabusy schedules and tell us what they were working on. They were happy to share.

Name: Roadrunner

TOP500 Rank: 10

Vital Stats: System: IBM BladeCenter QS22/LS21 Cluster, PowerXCell 8i 3.2 Ghz / Opteron DC 1.8 GHz, Voltaire Infiniband. Sustained performance: 1.04 Petaflop/s. That’s 122,400 cores of high-powered processing strength spread across 18 connected units. Each unit consists of 180 “triblade” computer nodes, all of which perform calculations in parallel. Each compute node in this cluster consists of two AMD Opteron dual-core processors plus four PowerXCell 8i processors used as computational accelerators. Fun fact: The accelerators used in Roadrunner are a special IBM-developed variant of the Cell processor used in the Sony PlayStation 3.

What Are You Up To?

Wouldn’t you like to know. Roadrunner belongs to the Department of Energy via Los Alamos National Lab. That means it often spends its processing time on rather ominous problems like nuclear weapons modeling and simulation to “assure the safety, security, and effectiveness of the U.S. nuclear deterrent.” In other words, Roadrunner’s work is super top-secret classified. But Roadrunner was willing to tell us–whilst glancing over both shoulders and dropping its voice slightly–that “models and simulations could include hydrodynamic mixing and turbulence of exotic materials under extreme conditions – temperatures at the core of the sun, time scales in the microseconds, and velocities of millions of miles per hour.”

Those kinds of calculations require either lots of time or lots of computing power. Roadrunner proudly supplies the latter. On a recent day (it wouldn’t tell us exactly which day), it ran 126 jobs across 512 of its 3,060 nodes. At any given time, there are 20-50 jobs lined up for Roadrunner–most of which aren’t the kind the DOE, or Roadrunner, cares to share with the larger world.

Catch up with more supercomputers here.