Supercomputers/Systems/JMA PRIMERGY CX2550 M7
Japan · operational · hpc
JMA PRIMERGY CX2550 M7
Also known as JMA eleventh-generation supercomputer (Kiyose)
Operated by Japan Meteorological Agency .
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 1581 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
- 2.55 PFlop/s
- Rpeak
- 3.38 PFlop/s
- Rmax ÷ Rpeak
- 75.4%
- Cores
- 55,552
- Power
- 438.03 kW
- Per watt
- 5.8 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.
How it compares
Ranked against the other machines in this dataset that report the same figure: those that first came into service within two years of JMA PRIMERGY CX2550 M7, and those in Japan. Computed from our tables; a metric is ranked only when at least eight peers report it.
| Metric | Value | Against its era | Against its country |
|---|---|---|---|
| Rmax | 2.55 PFlop/s | #221 of 234 · bottom 7% | #51 of 131 · top 38% |
| Energy efficiency | 5.8 GF/W | #108 of 121 · bottom 12% | #30 of 74 · top 40% |
| Rmax ÷ Rpeak | 75.4 % | #111 of 231 · top 48% | #64 of 130 · top 49% |
| Power draw | 438 kW | #71 of 126 · bottom 45% | #45 of 74 · bottom 41% |
Every metric is ranked largest-first, so a high power-draw rank means a big power draw, not a good one. Rmax ÷ Rpeak uses HPL-measured results only. Rankings move as machines are added; they describe this dataset, not the world.
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 PRIMERGY CX2550 M7, 496 nodes per HPC, two HPCs | Fujitsu | - | Verified | jma.go.jptop500.org |
| CPU | - Intel Xeon CPU Max 9480 56C 1.9GHz with HBM2e, two per node | Intel | - | Verified | jma.go.jptop500.org |
| Interconnect | NVIDIA InfiniBand NDR (Quantum-2) Interconnect Fat tree or dragonfly+ · 400 Gb/s per port · Under 0.6 microseconds InfiniBand NDR200, 200 Gbps per node | NVIDIA | - | Verified | jma.go.jptop500.org |
| Operating system | Red Hat Enterprise Linux Operating systems Linux distribution · Open source, commercial support subscription Red Hat Enterprise Linux 8.6 | Red Hat | - | Verified | jma.go.jptop500.org |
The read
The Japan Meteorological Agency's main numerical weather prediction supercomputer, built as two near-identical HPCs at the Kiyose computer centre (23 km west of JMA headquarters in central Tokyo): a main system for operational forecasts and a sub-system for development that takes over if the main one fails. JMA's 2025 NWP outline describes 496 Fujitsu PRIMERGY CX2550 M7 nodes per HPC (484 available, 12 spare), each with two Xeon Max 9480 (56 cores, 1.9 GHz, HBM2e memory, 128 GiB per node), InfiniBand NDR200, 3.295 PFlop/s peak per HPC excluding spares, RHEL 8.6 and Lustre storage of 9.5 PB (main) and 17.7 PB (sub). TOP500 lists the two HPCs as two identical entries (55,552 cores = 496 x 112, 2.55 PFlop/s Rmax, 3.38 PFlop/s Rpeak, 438 kW); this row records the higher-ranked one (TOP500 system 180278, 477th in June 2025) and the twin is TOP500 system 180279. Neither entry stayed on the November 2025 list. Date discrepancy: TOP500 gives installation year 2023 while JMA's outline says the system has been in operation since 5 March 2024, which is the date used here. Not the same machine as jma-primehpc-fx1000, the A64FX linear rainband system hosted in Fujitsu's cloud data centre, and it replaced the Cray XC50 pair (see jma-cray-xc50). The site is left blank because the existing JMA site row is the Tokyo headquarters, not Kiyose.
Timeline
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Change history
- 2026-10-29 Added JMA PRIMERGY CX2550 M7
Nearby in scale
The machines closest to JMA PRIMERGY CX2550 M7 by Rmax, smaller to larger.
Related systems
Same operator
- JMA PRIMEHPC FX1000 · Japan, operational, 2023
- JMA Cray XC50 · Japan, operational, 2018
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.