Supercomputers/Systems/Gyoukou
Japan · decommissioned · hpc
Gyoukou
Operated by JAMSTEC at Earth Simulator 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
- 19.14 PFlop/s
- Rpeak
- 28.19 PFlop/s
- Rmax ÷ Rpeak
- 67.9%
- Cores
- 19,860,000
- Power
- 1.35 MW
- Per watt
- 14.2 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 | - ZettaScaler-2.2 HPC system | ExaScaler | - | Verified | top500.orgen.wikipedia.org |
| Accelerator | PEZY-SC2 Accelerators MIPS64 (PE array) · 2,048C · 0.7 GHz 10,000 PEZY-SC2 modules, 2,048 processing elements each | PEZY Computing | 10,000 reported | Verified | top500.orgen.wikipedia.org |
| CPU | Intel Xeon D-1571 CPUs x86-64 · 16C · 1.3 GHz · 14 nm 1,250 Xeon D-1571 host processors | Intel | 1,250 reported | Verified | top500.orgen.wikipedia.org |
| Interconnect | Mellanox InfiniBand EDR Interconnect Fat tree · 100 Gb/s per 4x port · About 0.9 microseconds Infiniband EDR | Mellanox NVDANASDAQ
rolls up to NVIDIA | - | Reported | top500.org |
| Cooling | Single-phase immersion Cooling Full submersion in a dielectric bath · 100 kW per tank and above ExaScaler ZettaScaler-2.2 Fluorinert immersion cooling | ExaScaler | - | Reported | en.wikipedia.orgtop500.org |
The read
ExaScaler and PEZY Computing's ZettaScaler-2.2 system at JAMSTEC's Earth Simulator Building: 10,000 PEZY-SC2 accelerator modules (2,048 processing elements each) paired with 1,250 Intel Xeon D-1571 host processors on InfiniBand EDR, fully submerged in Fluorinert dielectric fluid. TOP500 and Wikipedia's independently-sourced figures agree on the Rmax (about 19.14 PFlop/s) and power draw (about 1,350 kW), so the tier is verified. First appeared on the June 2017 TOP500 list at rank 69 in a partial configuration, then reached rank 4 worldwide (and rank 5 on Green500 at 14.173 GFlops/W) at full scale in November 2017, one of the shortest reigns near the top of the list in this dataset: PEZY Computing's president was arrested in December 2017 on fraud charges tied to NEDO development subsidies used to fund the ZettaScaler line, a fact independently confirmed by TOP500's own news coverage, and Wikipedia states the machine was removed from JAMSTEC in April 2018 amid the fallout; the exact removal month rests on that single source, so the decommissioned_date fact itself is not independently cross-confirmed even though the overall system specs are.
Timeline
- 2017 Announced source
- 2017-06 First operational source
- 2017-11 List debut at #4 (November 2017) source
- 2018-04 Decommissioned 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
Change history
- 2026-09-24 Gyoukou added
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 |
|---|---|---|
| en.wikipedia.org | names system, part and count | PEZY-SC2, Intel Xeon D-1571, Mellanox InfiniBand EDR · counts: 10000, 1250 |
| top500.org | names system and part | PEZY-SC2, Intel Xeon D-1571, Mellanox InfiniBand EDR |
Checked 2026-10-09 by pnpm verify. Re-run it and the table changes with the web.
Further reading
Inside a node
Why accelerators exist, what the memory hierarchy costs, and how the CPU and accelerator merged onto one package.
The interconnect
Topologies, why latency and tail behaviour matter more than bandwidth, and how the fabric market consolidated.
Power and cooling
Why air ran out at 20 kW a rack, how warm-water cooling removes the chillers, and what PUE conceals.