The Japanese supercomputer Fugaku was crowned the new king of the Top 500 ranking by passing Summit, which held the title for two years. Fugaku has almost triple performance compared to its predecessor with a computing power of 415.5 Petaflops against 148.6 for a theoretical peak of 513.8 Petaflops against 200.8. As has been common for supercomputer kings for a long time, it uses the Linux operating system, specifically the Red Hat Enterprise Linux 8 distribution. An interesting novelty is that Fugaku is the first supercomputer king based on ARM architecture being built around 2.2GHz A64FX 48C processors. In the Top 500 ranking, only three other supercomputers are based on ARM architecture.
Installed at the RIKEN Center for Computational Science (R-CCS) in Kobe, Japan, the Fugaku supercomputer isn’t yet fully operational. It’s the successor of the K computer, which in June 2011 became the king of the category with over 8 Petaflops of computing power. It held the title for a year and today those performances no longer seem anything special, to the point that last year it was decommissioned while Fugaku was still in its planning stage. Now Fugaku brought the crown back to Japan after it was lost and passed between China and the USA right after the K computer lost it.
The Fugaku supercomputer is composed of 158,976 nodes, each containing an ARM A64FX 48C processor based on the Armv8.2-A SVE architecture for a total of 7,299,072 cores. The processors have 52 cores each, some of which are reserved for operating system activities. The nodes are used in part for actual processing and in part to manage the input/output, based on Fujitsu’s proprietary architecture called Torus fusion (Tofu) interconnect. Each node has 32 GByte of RAM.
These supercomputers are used for scientific research that requires significant computing power. Although not yet fully operational, the already active parts of the Fugaku supercomputer have already been used in research connected to the Covid-19 pandemic to study the characteristics of the coronavirus and identify potential drugs that can fight it and effective therapies.
The recent developments of the ARM architecture that led to the construction of the Fugaku supercomputer are interesting also because they could continue offering an important alternative to the architectures normally used for these projects. In general, the growth in the performance of supercomputers continues, and this enables the creation of increasingly sophisticated and precise software applications, crucial characteristics in scientific research.