For years, x86 processors and Linux have ruled supercomputing. Linux still runs 500 out of the TOP500 supercomputers in the world. For just about as long, x86 CPUs have dominated supercomputers — until now. On June 22, Japan’s Fugaku supercomputer, powered by Fujitsu’s 48-core A64FX SoC and running Red Hat Enterprise Linux (RHEL), became the first ARM-powered supercomputer to be dubbed the fastest computer in the world.