A64FX Prototype

Also known as Fugaku prototype

Operated by Fujitsu at Fujitsu Numazu Plant .

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: 2.00 PFlop/s
Rpeak: 2.36 PFlop/s
Rmax ÷ Rpeak: 84.7%
Cores: 36,864
Power: 118.48 kW
Per watt: 16.9 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 A64FX prototype system	Fujitsu 6702TSE	-	Reported	top500.org
CPU	Fujitsu A64FX CPUs Armv8.2-A SVE · 48C · 2.2 GHz · 7 nm 768 Fujitsu A64FX 48C 2GHz CPUs	Fujitsu 6702TSE	768 reported	Verified	info.archives.global.fujitsu 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

The read

The 768-CPU Fujitsu A64FX prototype of the Fugaku architecture at Fujitsu's Numazu Plant. Fujitsu's November 2019 release states 1.9995 PFlop/s LINPACK, 2.3593 PFlop/s peak and 16.876 GFlops/Watt, taking first place on the November 2019 Green500 with a CPU-only Arm SVE system; TOP500 lists the same 36,864 cores, 2.00 PFlop/s Rmax and 118.48 kW on Tofu interconnect D. It stayed on the Green500 afterwards, 6th in November 2020 (its TOP500 rank that edition was 239) and on the TOP500 from November 2019 (159th) to June 2022 (383rd). No later status is published, so the row is carried as operational as of its last list.

Timeline

2019 First operational source
2019-11-18 Announced source
2020-11 List debut at #6 (November 2020) source

Public list appearances

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

Site & facility

Fujitsu Numazu Plant

Location: Numazu, Japan
Commissioned: 2019

top500.org info.archives.global.fujitsu

Change history

2026-10-02 Added the A64FX Prototype of Fugaku

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
info.archives.global.fujitsu	names system, part and count	Fujitsu A64FX · counts: 768
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.