The full scale supercomputer is not quite as efficient as the prototype.
> The number nine system on the Green500 is the top-performing Fugaku supercomputer, which delivered 14.67 gigaflops per watt. It is just behind Summit in power efficiency, which achieved 14.72 gigaflops/watt.
https://www.nextplatform.com/2019/11/22/arm-supercomputer-ca...