ECMWF HPCF-AA

Operated by ECMWF at ECMWF Data Centre (Bologna Tecnopolo) .

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: 6.67 PFlop/s
Rpeak: 8.85 PFlop/s
Rmax ÷ Rpeak: 75.4%
Cores: 245,760
Power: 1.20 MW
Per watt: 5.6 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	- Eviden (Atos) BullSequana XH2000	Eviden ATOEPA rolls up to Atos	-	Verified	top500.org ecmwf.int
CPU	AMD EPYC 7742 (Rome) CPUs x86-64 · 64C · 2.25 GHz · 7 nm · 225 W AMD EPYC 7742 64C 2.25GHz	AMD AMDNASDAQ	-	Verified	top500.org ecmwf.int
Interconnect	NVIDIA InfiniBand HDR Interconnect Fat tree or dragonfly+ · 200 Gb/s per port · About 0.6 microseconds InfiniBand HDR200	NVIDIA NVDANASDAQ	-	Reported	top500.org

The read

One of the two identical clusters (Eviden, formerly Atos, calls them HPCF-AA and HPCF-AB) that make up ECMWF's Bologna High Performance Computing Facility, an Eviden BullSequana XH2000 built on AMD EPYC 7742 processors over InfiniBand HDR200. ECMWF signed the roughly EUR80 million Atos contract in 2020 and its own fact sheet states the Bologna facility took over production of operational forecasts on 18 October 2022, giving about 30 PFlop/s combined across all four of its clusters; TOP500 measures this one cluster alone. ECMWF states its own mission as numerical weather prediction, with half of the machine's time given to twice-daily operational forecast runs for its member states and the rest to research, including testing the next model upgrade. TOP500 is the only source for Rmax, Rpeak and core count, so the tier is reported.

Timeline

2020 Announced source
2022-10 First operational source
2023-11 List debut at #117 (November 2023) source

Public list appearances

Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.

#117: TOP500, November 2023 →

Site & facility

ECMWF Data Centre (Bologna Tecnopolo)

Location: Bologna, Italy
Commissioned: 2021

ecmwf.int hpcwire.com

Change history

2026-09-24 Added with a rank pointer on the edition where it ranked highest

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
ecmwf.int	names system only	-
top500.org	names system and part	AMD EPYC 7742 (Rome), NVIDIA InfiniBand HDR

Checked 2026-10-09 by pnpm verify. Re-run it and the table changes with the web.