Ultrahigh performance three-dimensional electromagnetic relativistic kinetic plasma simulation^a)

The algorithms, implementation details, and applications of VPIC, a state-of-the-art first principles 3D electromagnetic relativistic kinetic particle-in-cell code, are discussed. Unlike most codes, VPIC is designed to minimize data motion, as, due to physical limitations (including the speed of light!), moving data between and even within modern microprocessors is more time consuming than performing computations. As a result, VPIC has achieved unprecedented levels of performance. For example, VPIC can perform $∼0.17$ billion cold particles pushed and charge conserving accumulated per second per processor on IBM’s Cell microprocessor—equivalent to sustaining Los Alamos’s planned Roadrunner supercomputer at $∼0.56$ petaflop (quadrillion floating point operations per second). VPIC has enabled previously intractable simulations in numerous areas of plasma physics, including magnetic reconnection and laser plasma interactions; next generation supercomputers like Roadrunner will enable further advances.