An anonymous reader writes: A supercomputer like the upcoming Trinity machine is the only class of system that could adequately tackle what is known as “The Problem” in the weapons stockpile world. Their multiphysics 3D simulation, which (let your imagination run wild on this horror) factors in complex models that simulate thermonuclear burn, fission, hydrodynamics, and the photonic interactions from radiation.
Although the existing Cielo machine is far from puny, the code could only run on half the machine after a three-to-four day wait for an eight hour run because of so many other projects eating the machine. Aside from that more practical concern, nodes cannot go down during such a simulation and fast interaction between nodes is critical.