Going into shutdown. The Commerce Department blacklisted five more Chinese entities yesterday, all of which are involved in the production of supercomputers. By total number of units, China is the world leader in supercomputing, with 227 supercomputers compared to 109 in the U.S. - however the U.S. has the world's two fastest units. Supercomputers can perform over a billion-billion computations a second and are used in weapon design and advanced encryption. Like much China tech, China's supercomputers are built using U.S. components from suppliers like AMD, Advanced Micro, Intel and Nvidia. Wall Street Journal