What just happened? The world's fastest supercomputer has gone online at the Lawrence Livermore National Laboratory (LLNL) in California. Called "El Capitan," the machine was unveiled earlier this month after around eight years of research and development. It will be used to secure the US nuclear stockpile and for classified research. El Capitan can reach a peak performance of 2.746 exaFLOPS, making it the National Nuclear Security Administration's first exascale supercomputer. It's the world's third exascale machine after the Frontier supercomputer at Oak Ridge National Laboratory in Tennessee and the Aurora supercomputer at the Argonne Leadership Computing Facility, also in Illinois.The world's fastest supercomputer is powered by more than 11 million CPU and GPU cores integrated into 43,000+ AMD Instinct MI300A accelerators. Each MI300A APU comprises an EPYC Genoa 24-core CPU clocked at 1.8GHz and a CDNA3 GPU integrated onto a single organic package, along with 128GB of HBM3 memory.According to Pythagoras Watson, the team lead of the advanced technology system at LLNL, the system's peak performance is 2.79 quintillion calculations per second. As a measure of how astronomically large that number is, Watson explained to CBS News that if you went back in time 2.79 quintillion seconds, you'd arrive more than 70 billion years before the Big Bang.Built at a cost of around $600 million, the world's newest supercomputer was primarily designed to safeguard and secure the US nuclear arsenal, but it will also perform other classified tasks related to national security, including AI and machine learning workloads. It will also solve problems in materials science and physics.El Capitan was commissioned by the U.S. Department of Energy as part of its CORAL-2 program to replace the Sierra supercomputer, which was deployed in 2018. While Sierra is still in service, El Capitan far exceeds its speed and efficacy with 18 times faster performance. As pointed out by Live Science, Sierra is still operational, and was recently ranked as the 14th most-powerful supercomputer globally. // Related StoriesEl Capitan, which shares its name with the famous granite rock formation at Yosemite National Park, became fully operational last year, achieving a score of 1.742 exaFLOPS in the High-Performance Linpack (HPL) benchmark, which is used globally to judge supercomputing speeds. According to the LLNL, it would take a million smartphones working on a single calculation at the same time to match what El Capitan can do in one second.