Supercomputers/Systems/Fugaku
Japan · operational · mixed
Fugaku
Quantum: linked to RIKEN IBM Quantum System Two (156 superconducting qubits)
Deep dive: Fugaku: the CPU-only No. 1 and its successor
Operated by RIKEN at RIKEN Center for Computational Science .
Researched with AI assistance, checked by scripts. These rows were researched by AI agents reading public operator, laboratory and vendor sources, appended by scripts and checked by automated validation; no subject-matter expert has reviewed them (how this site is made). A mechanical second-reader pass has since fetched every cited source: 1350 of 1540 systems have a readable citation that names them, and 64 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
- 442.0 PFlop/s
- Rpeak
- 537.2 PFlop/s
- Rmax ÷ Rpeak
- 82.3%
- Cores
- 7,630,848
- Power
- 29.90 MW
- Per watt
- 14.8 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 | Fujitsu | - | Verified | r-ccs.riken.jpglobal.fujitsu |
| CPU | Fujitsu A64FX CPUs Armv8.2-A SVE · 48C · 2.2 GHz · 7 nm A64FX 48C 2.2GHz | Fujitsu | 158,976 reported | Verified | r-ccs.riken.jpglobal.fujitsu |
| Interconnect | Fujitsu Tofu Interconnect D Interconnect 6D mesh/torus · 6.8 GB/s per link per direction Tofu interconnect D | Fujitsu | - | Verified | r-ccs.riken.jpglobal.fujitsu |
| Storage | Fujitsu FEFS Storage Lustre-based parallel filesystem · Roughly 150 PB across multiple volumes on Fugaku FEFS Fujitsu Exabyte File System | Fujitsu | - | Verified | r-ccs.riken.jpwiki.lustre.org |
| Cooling | Direct liquid cooling, warm water Cooling Direct-to-chip cold plates, facility water loop · Removes 90+ percent of node heat to liquid direct water cooling | Fujitsu | - | Reported | r-ccs.riken.jpglobal.fujitsu |
| Operating system | Red Hat Enterprise Linux Operating systems Linux distribution · Open source, commercial support subscription OS Red Hat Enterprise Linux 8 | Red Hat | - | Verified | r-ccs.riken.jptop500.org |
| Operating system | McKernel Operating systems Lightweight multi-kernel (IHK-partitioned), co-resident with Linux · Research software, RIKEN-developed light-weight multi kernel operating system McKernel | RIKEN | - | Verified | r-ccs.riken.jpnetlib.org |
The read
158,976 A64FX nodes, no accelerators, no separate NIC: the Tofu D interconnect is on the CPU package. The shortest bill of materials of any modern leadership system: one company supplies the processor, the memory interface, the fabric and the integration. It is the counterexample to the assumption that top-end compute necessarily implies a multi-vendor supply chain, and the reason our accelerator-share chart has to handle a null accelerator role rather than treating every system as heterogeneous.
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
RIKEN Center for Computational Science
- Location
- Kobe, Japan
- Cooling
- Direct liquid cooling (warm water)
- Commissioned
- 2010
Change history
- 2026-09-22 Gained a Green500 rank pointer (#54 on the 2023-11 list)
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.
None of the cited sources could be read from our network: the hosts returned bot challenges or did not respond. This check says nothing about the citations either way. See how this check works.
| Cited source | Result | Found on the page |
|---|---|---|
| global.fujitsu | could not be fetched | - |
| r-ccs.riken.jp | could not be fetched | - |
Checked 2026-10-18 by pnpm verify. Re-run it and the table changes with the web.
Related news
- Fugaku takes the top position with no accelerators · RIKEN Center for Computational Science158,976 A64FX nodes, on-package HBM, and the Tofu fabric integrated onto the processor die. The shortest bill of materials of any modern leadership system.
Further reading
Power and cooling
Why air ran out at 20 kW a rack, how warm-water cooling removes the chillers, and what PUE conceals.
Inside a node
Latency-optimised versus throughput-optimised processors, NUMA, and the end of the host-to-device copy.
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.