COMA (PACS-IX)

Also known as Cluster Of Many-core Architecture processors; PACS-IX

Operated by University of Tsukuba at Tsukuba Center for Computational Sciences .

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: 1092 of 1153 systems have a readable citation that names them, and 40 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: 746.00 TFlop/s
Rpeak: 998.50 TFlop/s
Rmax ÷ Rpeak: 74.7%
Cores: 55,664
Power: 365.8 kW
Per watt: 2.0 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 CS300 cluster supplied by Cray	Cray HPENYSE rolls up to Hewlett Packard Enterprise	-	Reported	ccs.tsukuba.ac.jp top500.org
Accelerator	- Intel Xeon Phi 7110P coprocessors, 786 in total	Intel INTCNASDAQ	786 reported	Reported	ccs.tsukuba.ac.jp top500.org
CPU	- Intel Xeon E5-2670 v2 10C 2.5GHz, two per node on 393 nodes	Intel INTCNASDAQ	-	Reported	ccs.tsukuba.ac.jp top500.org
Interconnect	Mellanox InfiniBand FDR Interconnect Fat tree · 56 Gb/s per 4x port · About 1 microsecond InfiniBand FDR interconnect	NVIDIA NVDANASDAQ	-	Reported	top500.org

The read

The ninth generation of Tsukuba's PACS/PAX supercomputer series, a Cray CS300 delivered to the Center for Computational Sciences and put into operation on 15 April 2014. Its 393 compute nodes each carry two Xeon E5-2670 v2 and two Xeon Phi 7110P coprocessors (786 in total) on FDR InfiniBand; the centre quotes 1.001 PFlop/s peak against the 0.9985 PFlop/s on the TOP500, where it ranked 52nd in June 2014. It was the largest Xeon Phi cluster in Japan at the time and a test bed for the later JCAHPC machine.

Timeline

2014-04 Announced source
2014-04-15 First operational source
2014-06 List debut at #52 (June 2014) source

Public list appearances

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

#52: TOP500, June 2014 →

Site & facility

Tsukuba Center for Computational Sciences

Location: Tsukuba, Japan
Commissioned: 1996

museum.ipsj.or.jp netlib.org

Change history

2026-10-07 Added COMA (PACS-IX)

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
ccs.tsukuba.ac.jp	does not name this system	-
top500.org	names system and part	Mellanox InfiniBand FDR

Checked 2026-10-09 by pnpm verify. Re-run it and the table changes with the web.