As of November 2021, Fugaku is the most powerful computer in the world, with a theoretical peak performance of 514 PFlop/s. Fugaku is hosted by RIKEN Center for Computational Science in the city of Kobe, Japan, and the system is manufactured by Fujitsu.
Fukagu is a bit of an exception in the top 10 as it uses ARM A64FX processors. Each processor has 48 computational cores running with a clock frequency of 2.2 GHz. Each node contains a single CPU and additional assistant cores (two in computational nodes and four in I/O nodes), and in total, there are 7,299,072 cores in the system. The total amount of memory is 4,866,048 gigabytes.
The declared power consumption of Fugaku is 28 MW. For perspective, ordinary sauna stoves used in Finnish saunas have a power consumption of around nine kW, which means the 28 MW used by the Japanese supercomputer equals that of around 3,100 sauna stoves.
Summit is hosted by Oak Ridge National Laboratory, USA, and it is a prime example of a modern-day accelerated supercomputer based on GPUs. Summit has in total 4,608 nodes, each of which contains two IBM POWER9 processors and six NVIDIA Volta V100 GPUs. The theoretical peak performance of the system is 201 PFlop/s. The total amount of memory is over 10,000,000 gigabytes, and the declared power consumption is 10 MW. Yet again, that is around 1100 saunas in terms of power draw.
The Chinese Sunway TaihuLight was the world’s fastest supercomputer for two years in 2016–2017, and it is still (in November 2021) number four on the list with a theoretical peak performance of 125 PFlop/s. Although the Chinese-designed CPU cores are not particularly fast, running only at 1.45 GHz, there are a total of 256 of them in each CPU. In total, there are over 10,000,000 cores in the system and over 1,000,000 gigabytes of memory.
The system runs its own Linux-based operating system, and the programming environment is also heavily customized in order to support the Sunway CPU architecture. The declared power consumption is 15 MW. This time we’re looking at around 1600 saunas drawing power simultaneously.