Simulation for the Rest of Us, or How to Have Fun with a Supercomputer

When it comes to simulations these days, I tend to think of "Assassin's Creed," "Call of Duty 4," and maybe "Guitar Hero III: Legends of Rock," among others. What doesn't spring to mind is stuff like A Micron-Scale Atomistic Simulation of Kelvin-Helmholtz Instability.

While simulating Kelvin-Helmholtz instability doesn't sound like a lot of fun for some of us, my guess is that it was fun for a team of scientists from Lawrence Livermore National Laboratory and IBM, which received the 2007 Gordon Bell Prize for a first-of-a-kind simulation of Kelvin-Helmholtz instability in molten metals. The fun part is that they didn't use a PlayStation 3, but instead BlueGene/L, the world's fastest supercomputer. By performing extremely large-scale molecular dynamics simulations, the team--Jim Glosli, Kyle Caspersen, David Richards, Robert Rudd, Fred Streitz, and John Gunnels--was able to study how a Kelvin-Helmholtz instability develops from atomic scale fluctuations into micron-scale vortices.

But since traditional programming techniques that rely on the hardware or operating system to correct errors don't work well with computers having more than 200,000 CPUs (like BG/L), the team came up with a way for the application itself to help correct errors and failures. They figured out that the application, which has a complete understanding of the calculation being run, can evaluate the errors and decide the most efficient strategy for recovery. By implementing a strategy to mitigate cache memory, for instance, the application could run essentially forever without errors.

Now doesn't that sound like fun?

-- Jonathan Erickson
jerickson@ddj.com

Posted by Jon Erickson at 07:23 PM  Permalink