Supercomputers/Systems/HOKUSAI BigWaterfall 2
Japan · operational · hpc
HOKUSAI BigWaterfall 2
Also known as HBW2
Operated by RIKEN .
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
- -
- Rpeak
- 2.12 PFlop/s
- Rmax ÷ Rpeak
- -
- Cores
- 34,944
- 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 Server PRIMERGY CX2550 M7, 312 nodes | Fujitsu | - | Reported | i.riken.jp |
| CPU | - Intel Xeon Max (1.9 GHz, 56 cores, HBM2e), 2 CPUs per node | Intel | 624 estimated | Reported | i.riken.jphpci-office.jp |
| Interconnect | NVIDIA InfiniBand NDR (Quantum-2) Interconnect Fat tree or dragonfly+ · 400 Gb/s per port · Under 0.6 microseconds InfiniBand NDR 400 Gbps | NVIDIA | - | Reported | i.riken.jphpci-office.jp |
| Storage | DDN EXAScaler Storage Lustre appliance EXAScaler Lustre file system, 9.8 PB, 400 GB/s | DDN | - | Reported | i.riken.jp |
The read
Current HOKUSAI massively parallel system, in service from 4 December 2023 through November 2029: 312 Fujitsu PRIMERGY CX2550 M7 nodes with two Intel Xeon Max (56-core, HBM2e) CPUs each, InfiniBand NDR 400 Gbps, 2.12 PFLOPS peak and a 9.8 PB EXAScaler Lustre store at 400 GB/s. The HPCI allocation page lists 156 nodes as the maximum shared with HPCI users, a subset of the full machine. No GPUs. Not on the TOP500.
Timeline
- 2023-12-04 First operational source
Change history
- 2026-10-02 Added HOKUSAI BigWaterfall 2, RIKEN's 2023 Xeon Max HBM cluster
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 |
|---|---|---|
| i.riken.jp | names system only | - |
| hpci-office.jp | names system and part | NVIDIA InfiniBand NDR (Quantum-2) |
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.