This is in large part because of the power of today’s most advanced supercomputers, which are now approaching exascale, meaning they can carry out a billion billion operations per second. Only four such machines exist, according to the Top500 list. Diesmann and his team are looking at running large-scale brain simulations on one of these systems called JUPITER, short for Joint Undertaking Pioneer for Innovative and Transformative Exascale Research, based in Germany.