Supercomputers/Systems/Sekirei (ISSP System B)
Japan · decommissioned · hpc
Sekirei (ISSP System B)
Also known as Sekirei; ISSP System B (2015); SGI ICE XA/UV
Operated by ISSP Supercomputer Center at ISSP Supercomputer 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
- 1.18 PFlop/s
- Rpeak
- 1.52 PFlop/s
- Rmax ÷ Rpeak
- 77.5%
- Cores
- 38,016
- Power
- 580.9 kW
- Per watt
- 2.0 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 | - SGI ICE XA/UV hybrid system supplied by HPE (SGI) | Hewlett Packard Enterprise | - | Reported | top500.orgmdcl.issp.u-tokyo.ac.jp |
| Accelerator | - NVIDIA Tesla K40 GPUs, 2 per node on 288 accelerator nodes | NVIDIA | 576 reported | Reported | mdcl.issp.u-tokyo.ac.jptop500.org |
| CPU | - Intel Xeon E5-2680 v3 12C 2.5GHz, 1584 CPU nodes with 2 processors each | Intel | 3,168 reported | Reported | top500.orgmdcl.issp.u-tokyo.ac.jp |
| Interconnect | Mellanox InfiniBand FDR Interconnect Fat tree · 56 Gb/s per 4x port · About 1 microsecond FDR InfiniBand interconnect | NVIDIA | - | Reported | mdcl.issp.u-tokyo.ac.jptop500.org |
The read
System B of the Institute for Solid State Physics supercomputer centre at the University of Tokyo, an SGI ICE XA/UV hybrid in service from July 2015 to June 2020. ISSP counts 1,584 CPU nodes (dual Xeon E5-2680 v3), 288 accelerator nodes with two NVIDIA Tesla K40 each, and 19 large-memory fat nodes, linked by FDR InfiniBand, for 2.6 PFlop/s theoretical peak in total. The TOP500 entry recorded here covers only the CPU nodes (38,016 cores); the accelerator partition was listed separately as Sekirei-ACC. It ranked 54th in June 2015.
Timeline
- 2015-06 List debut at #54 (June 2015) source
- 2015-07 First operational source
- 2020-06 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
- 2026-10-07 Added Sekirei (ISSP System B)
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 |
|---|---|---|
| mdcl.issp.u-tokyo.ac.jp | does not name this system | - |
| top500.org | names system and part | Mellanox InfiniBand FDR |
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.