Japan · decommissioned · hpc

ATERUI I

Also known as ATERUI; NAOJ Cray XC30 ATERUI

Operated by National Astronomical Observatory of Japan at NAOJ Mizusawa Campus .

Phase 1 seed dataset, compiled by hand. These rows were built from public operator, laboratory and vendor sources. A mechanical second-reader pass has since fetched every cited source: 1263 of 1345 systems have a readable citation that names them, and 56 are genuinely weakly sourced. Every claim carries its source and a confidence tier. Treat anything below verified as a lead, not a citation.

Measured performance

Rmax: 801.40 TFlop/s
Rpeak: 1.06 PFlop/s
Rmax ÷ Rpeak: 75.7%
Cores: 25,440
Power: 568.5 kW
Per watt: 1.4 GF/W

Figures are as last publicly reported for the configuration described below, not a live measurement. Where a system was upgraded in place, the post-upgrade configuration is shown and the earlier one appears in the timeline.

What this machine is made of

One row per supplier relationship. “Supplier at build” is the company that shipped the part at the time; where that company has since been acquired, the parent it rolls up to today is shown beside it. That distinction is what makes ticker-level aggregation possible across a thirty-year dataset.

Role	Part	Supplier at build	Quantity	Confidence	Source
Integrator	- Cray XC30 (NAOJ designation; TOP500 labels it XC40), prime manufacturer Cray Japan	Cray HPENYSE rolls up to Hewlett Packard Enterprise	-	Verified	nao.ac.jp top500.org
CPU	Intel Xeon E5-2690 v3 CPUs x86-64 · 12C · 2.6 GHz · 22 nm · 135 W Intel Xeon E5-2690 v3 12C 2.6GHz (Haswell), 24 cores per node, 25,440 cores	Intel INTCNASDAQ	-	Verified	nao.ac.jp top500.org
Interconnect	Cray Aries Interconnect Dragonfly · About 10 GB/s per direction · Around 1 microsecond Cray Aries interconnect	Cray HPENYSE rolls up to Hewlett Packard Enterprise	-	Reported	top500.org
Operating system	Cray Linux Environment Operating systems Linux, Cray-customised · Proprietary layer over open-source Linux Cray Linux Environment	Cray HPENYSE rolls up to Hewlett Packard Enterprise	-	Reported	top500.org

The read

Cray supercomputer of the National Astronomical Observatory of Japan's Center for Computational Astrophysics, installed at the Mizusawa campus in Oshu, Iwate. NAOJ calls it the Cray XC30 ATERUI: common use began on 1 April 2013, it was upgraded in September 2014 from 502 TFlop/s to 1.058 PFlop/s peak with Intel Haswell 2.6 GHz CPUs, and its page gives 1,060 nodes, 25,440 cores, 135.6 TB of memory and 820 TB of disk; operation ended in March 2018, when ATERUI II took over. TOP500 lists the same 25,440 cores (as an XC40 with Xeon E5-2690v3 on Aries), 801.4 TFlop/s Rmax, 1,058.3 TFlop/s Rpeak and 568.5 kW, with 64th place on the June 2013 list and last seen in November 2017.

Timeline

2013-04-01 First operational source
2013-06 List debut at #64 (June 2013) source
2018-03 Decommissioned source

Public list appearances

Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.

#64: TOP500, June 2013 →

Site & facility

NAOJ Mizusawa Campus

Location: Oshu, Iwate, Japan

nao.ac.jp

Change history

2026-10-09 Added ATERUI I

Source check

We fetched this system's own citations and recorded whether each page actually mentions it. This is a corroboration signal, not a fact check, and it is published so you can see how well the sourcing holds up rather than take it on trust.

Cited source	Result	Found on the page
nao.ac.jp	names system only	-
top500.org	names system and part	Intel Xeon E5-2690 v3, Cray Aries, Cray Linux Environment

Checked 2026-10-13 by pnpm verify. Re-run it and the table changes with the web.