National Astronomical Observatory of Japan

Massively Parallel Computer Cray XC30 “ATERUI”

What was ATERUI?

The massively parallel computer Cray XC30 “ATERUI” was a supercomputer for astrophysical simulations installed at the Mizusawa VLBI Observatory. The common use for ATERUI started on April 1, 2013. With a high-speed network, ATERUI easily enabled astronomers to access and transfer data from Japan and overseas.

In astronomy, it is indispensable to quantify various physical phenomena through observations and also interpret them theoretically. And in science, it is essential to perform experiments to reproduce the results and verify the correctness of the theoretical models. However, the scale of most of the phenomena we handle in astronomy cannot be reproduced in the laboratory. Supercomputers do great in these cases. By solving more computations than a human being could with high-performance computational power, it becomes possible to virtually reproduce various astrophysical phenomena inside the computer. This is why supercomputers are called “Telescopes for Theoretical Astronomy.” Using ATERUI, various large-scale, high-precision simulations were carried out continuously. ATERUI made great contributions to the development of astronomy. The operation was finished in March, 2018.

Massively Parallel Computer Cray XC30 “ATERUI”


LocationNAOJ Mizusawa (Hoshigaoka, Mizusawa, Oshu, Iwate, Japan)
Prime manufacturerCray Japan Inc.
System summary of Cray XC30 (scalar-type parallel computer)Number of nodes: 1060
CPU:Intel HASWELL 2.6 gigahertz
Number of Cores: 25,440 (entire system) and 24 per one node
Theoretical Peak Performance: 1058 Tflops
Main Memory: 135.6 TB (entire system) and 128 GB (per one node)
Disk: 820 TB


April 1, 2013Common use began.
September 2014Upgraded.
March 2018Operation ended.

What is the reason for the nickname ATERUI?

Aterui was a leader of the Emishi who lived in the Mizusawa area of Iwate prefecture 1200 years ago. He was a hero who fought bravely with his comrades against the Imperial Court’s hostile expedition. ATERUI is nicknamed after this brave hero in hopes that it will boldly confront the formidable enigmas of the Universe. Reimagined tensyo kanji (traditional block style lettering) for ATERUI (阿弖流為) that imitate an electronic circuit are written on the housing.