The El Capitan supercomputer at the Lawrence Livermore National LaboratoryGarry McLeod/Lawrence Livermore National LaboratoryThe top spot in the league table of the worlds most powerful computers has changed hands, with one supercomputer built for US national security research ousting another.Top500, the definitive list of the most capable computers, is based on a single metric: how fast a machine can solve vast numbers of equations, measured in floating-point operations per second, or FLOPS. A machine called Frontier built in 2022 was the first publicly acknowledged to have reached the exascale a billion billion FLOPS. AdvertisementFrontier was created by Oak Ridge National Laboratory in Tennessee to carry out nuclear weapon simulations, but also to work on a range of complex scientific problems such as climate modelling, nuclear fusion simulation and drug discovery.Now, Lawrence Livermore National Laboratory (LLNL) in California has created El Capitan, which is capable of 1.742 exaFLOPS, more than any other supercomputer.The machine has been built in collaboration with the National Nuclear Security Administration, an arm of the Department of Energy dedicated to developing nuclear weapons science under tight security. The agency was formed in 2000 after the discovery that nuclear secrets had leaked to China from the Department of Energy.El Capitan will essentially provide the vast computational power necessary to ensure the effectiveness of the US nuclear deterrent without having to carry out physical nuclear testing. LLNL claims that complex, high-resolution 3D simulations of nuclear explosions that would take months on Sierra, its most powerful system until now, will be done in just hours or days on El Capitan.Topics:computing