Are the world's most powerful supercomputers operating in secret?

MattSparkes writes: A new supercomputer called Frontier has been widely touted as the world’s first exascale machine – but was it really? Although Frontier, which was built by the Oak Ridge National Laboratory in Tennessee, topped what is generally seen as the definitive list of supercomputers, others may already have achieved the milestone in secret.

Some owners prefer not to release a benchmark figure, or even publicly reveal a machine’s existence. Simon McIntosh-Smith at the University of Bristol, UK points out that not only do intelligence agencies and certain companies have an incentive to keep their machines secret, but some purely academic machines like Blue Waters, operated by the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, are also just never entered.