Japan · operational · hpc

TOKI-SORA

Also known as JSS3

Operated by JAXA at JAXA Chofu Aerospace Center .

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: 16.59 PFlop/s
Rpeak: 19.46 PFlop/s
Rmax ÷ Rpeak: 85.3%
Cores: 276,480
Power: -
Per watt: - 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	- Fujitsu PRIMEHPC FX1000	Fujitsu 6702TSE	-	Reported	top500.org jss.jaxa.jp
CPU	Fujitsu A64FX CPUs Armv8.2-A SVE · 48C · 2.2 GHz · 7 nm A64FX 48C 2.2GHz	Fujitsu 6702TSE	276,480 reported	Reported	top500.org
Interconnect	Fujitsu Tofu Interconnect D Interconnect 6D mesh/torus · 6.8 GB/s per link per direction Tofu interconnect D	Fujitsu 6702TSE	-	Reported	top500.org
Storage	- DDN AI storage for large-scale Earth observation numerical analysis	DDN	-	Reported	ddn.com

The read

The main computing system of JAXA Supercomputer System generation 3 (JSS3), housed at the Chofu Aerospace Center. A Fujitsu PRIMEHPC FX1000 built on the same A64FX-plus-Tofu-D architecture as Fugaku, with no separate accelerator or NIC vendor in its bill of materials, used for aerospace and earth-observation numerical simulation and later paired with DDN AI storage for large-scale Earth observation data analysis. TOP500 lists Rmax 16.59 PFlop/s and Rpeak 19.46 PFlop/s across 276,480 cores, first appearing on the November 2020 list at rank 19; JAXA's own JSS site confirms the TOKI-SORA name and its later benchmark placements (TOP500 #39 in November 2022) but does not itself republish the exact PFlop/s figures, so the tier stays reported rather than verified.

Timeline

2020-11 List debut at #19 (November 2020) source
2020-11 First operational source

Public list appearances

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

#19: TOP500, November 2020 →

Site & facility

JAXA Chofu Aerospace Center

Location: Chofu, Japan
Commissioned: 2020

jss.jaxa.jp top500.org

Change history

2026-09-24 TOKI-SORA added, JAXA's A64FX-based JSS3 main computing system at Chofu

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
top500.org	names system, part and count	Fujitsu A64FX, Fujitsu Tofu Interconnect D · counts: 276480
jss.jaxa.jp	names system only	-

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