Supercomputers/Systems/Flow
Japan · operational · hpc
Flow
Operated by Information Technology Center, Nagoya University at Nagoya University Information Technology 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
- 6.62 PFlop/s
- Rpeak
- 7.79 PFlop/s
- Rmax ÷ Rpeak
- 85.0%
- Cores
- 110,592
- 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 | - | Verified | top500.orgicts.nagoya-u.ac.jp |
| CPU | Fujitsu A64FX CPUs Armv8.2-A SVE · 48C · 2.2 GHz · 7 nm 2,304 A64FX nodes, A64FX 48C 2.2GHz | Fujitsu | 2,304 estimated | Verified | icts.nagoya-u.ac.jptop500.org |
| Interconnect | Fujitsu Tofu Interconnect D Interconnect 6D mesh/torus · 6.8 GB/s per link per direction Tofu interconnect D | Fujitsu | - | Reported | top500.org |
| Operating system | Red Hat Enterprise Linux Operating systems Linux distribution · Open source, commercial support subscription Red Hat Enterprise Linux | Red Hat | - | Reported | top500.org |
The read
Nagoya University's Fujitsu PRIMEHPC FX1000, the first regular service of a Fugaku-type machine, with 2,304 A64FX nodes on Tofu D. Service began on 1 July 2020 and TOP500 ranked it 36th that June, listing it until November 2025. TOP500 covers only this Type I subsystem, and lists the GPU subsystem separately. The centre's total for all four subsystems is 15.88 PFlop/s, so the figures here are the A64FX partition's. Nagoya quotes 7.782 PFlop/s peak against TOP500's 7.79, the same figure rounded. TOP500 is the only source for Rmax, Rpeak and core count, so the tier is reported.
Timeline
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Site & facility
Nagoya University Information Technology Center
- Location
- Nagoya, Japan
Change history
- 2026-09-20 Added with a rank pointer on the edition where it ranked highest
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 |
|---|---|---|
| icts.nagoya-u.ac.jp | names system, part and count | Fujitsu A64FX · counts: 2304 |
| top500.org | names system and part | Fujitsu A64FX, Fujitsu Tofu Interconnect D |
Checked 2026-10-09 by pnpm verify. Re-run it and the table changes with the web.
Further reading
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.
Inside a node
Latency-optimised versus throughput-optimised processors, NUMA, and the end of the host-to-device copy.
The interconnect
Topologies, why latency and tail behaviour matter more than bandwidth, and how the fabric market consolidated.