Newest Pleiades racks

At NASA's advanced supercomputing facility, at its Ames Research Center in Mountain View, Calif., the space agency maintains Pleiades, which at a current official measurement of 973 teraflops--or 973 trillion floating point operations per second--is the world's sixth-most powerful computer.

Pleiades is used by NASA personnel across the agency for research in earth and space sciences, and for conducting giant simulations. The machine is almost fully subscribed--meaning that it is in use 24 hours a day, seven days a week.

Inside the computing center, the agency maintains rack after rack of the SGI machines that make up Pleiades, most of which have 512 cores, or about 6 teraflops. But recently, the center added 32 new racks with 768 cores--some of which are seen here.

Things move fast in the world of supercomputers. When Pleiades was debuted in November 2008, it was measured at 487 teraflops and was the third-most powerful computer. Now, almost a year and a half later, it has dropped to sixth place on the list, but has doubled its power.