Japan · operational · hpc

JFRS-1

Also known as Japan Fusion Reactor Simulator 1

Operated by QST at QST Rokkasho Fusion Institute .

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: 2.79 PFlop/s
Rpeak: 4.19 PFlop/s
Rmax ÷ Rpeak: 66.6%
Cores: 54,560
Power: 697.51 kW
Per watt: 4.0 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 XC50-LC	Cray HPENYSE rolls up to Hewlett Packard Enterprise	-	Verified	top500.org iferc.org
CPU	Intel Xeon Gold 6148 CPUs x86-64 · 20C · 2.4 GHz · 14 nm · 150 W Xeon Gold 6148 20C 2.4GHz, 2 per node, 1,370 nodes	Intel INTCNASDAQ	1,370 reported	Verified	top500.org iferc.org
Interconnect	Cray Aries Interconnect Dragonfly · About 10 GB/s per direction · Around 1 microsecond 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 XC50-LC at the QST Rokkasho Fusion Institute, used entirely for plasma physics and fusion technology research. TOP500 lists 54,560 cores of Xeon Gold 6148 20C 2.4GHz on the Aries interconnect, 2.79 PFlop/s Rmax, 4.19 PFlop/s Rpeak and 697.51 kW; it ranked 209th in June 2022 (entry recorded here) and was still listed in June 2025. The IFERC site states 1,370 nodes of 2x20 cores with 192 GB each and 4.2 PFlop/s peak, available to Japanese fusion scientists from June 2018 and to the IFERC-CSC project from April 2020. It succeeded the Helios cluster.

Timeline

2018-06 First operational source
2022-06 List debut at #209 (June 2022) source

Public list appearances

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

#209: TOP500, June 2022 →

Site & facility

QST Rokkasho Fusion Institute

Location: Rokkasho, Aomori, Japan
Commissioned: 2025

nifs.ac.jp nsrp.nifs.ac.jp

Change history

2026-10-02 Added JFRS-1, QST Rokkasho

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 and part	Intel Xeon Gold 6148, Cray Aries, Cray Linux Environment
iferc.org	names system, part and count	Intel Xeon Gold 6148 · counts: 1370

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