Supercomputers/Systems/fortytwo
Germany · operational · ai training
fortytwo
Also known as hessian.AI 42; hessian.AI fortytwo
Operated by hessian.AI at GSI Helmholtz Centre (Darmstadt) .
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
- 7.94 PFlop/s
- Rpeak
- 8.83 PFlop/s
- Rmax ÷ Rpeak
- 89.9%
- Cores
- 64,512
- Power
- 352.8 kW
- Per watt
- 22.5 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 | - HPE Apollo 6500 | Hewlett Packard Enterprise | - | Reported | top500.org |
| Accelerator | - 632 NVIDIA A100 80GB GPUs | NVIDIA | 632 reported | Verified | hessian.aitop500.org |
| Accelerator | Graphcore IPU Accelerators Graphcore IPU · TSMC 7nm · 300 W Four Graphcore IPU units | Graphcore | 4 reported | Reported | hessian.ai |
| CPU | - AMD EPYC 7313 16C 3GHz | AMD | - | Reported | top500.org |
| Interconnect | NVIDIA InfiniBand HDR Interconnect Fat tree or dragonfly+ · 200 Gb/s per port · About 0.6 microseconds Infiniband HDR (NVIDIA Quantum) | NVIDIA | - | Reported | top500.orghessian.ai |
The read
The AI supercomputer of the Hessian Center for Artificial Intelligence (hessian.AI), announced on 15 June 2023 and housed in the Green IT Cube on the GSI/FAIR campus in Darmstadt. hessian.AI describes 80 compute nodes with 632 NVIDIA A100 80GB GPUs plus four Graphcore IPU units, an NVIDIA Quantum InfiniBand network and 1.2 PB of flash storage (IBM Spectrum Scale), with cooling under seven percent of the electrical power used for computing. TOP500 lists it as an HPE Apollo 6500 with AMD EPYC 7313 hosts, 64,512 cores, Rmax 7.94 PFlop/s, Rpeak 8.83 PFlop/s and 352.8 kW. It ranked 98th on the November 2023 list; the June 2024 to November 2025 lists carry it at 120th, 146th, 174th and 204th.
Timeline
- 2023 First operational source
- 2023-06-15 Announced source
- 2023-11 List debut at #98 (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.
Site & facility
Change history
- 2026-10-02 Added fortytwo, the hessian.AI A100 supercomputer in Darmstadt, 98th on the November 2023 TOP500
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 |
|---|---|---|
| hessian.ai | names system, part and count | Graphcore IPU, NVIDIA InfiniBand HDR · counts: 4 |
| top500.org | does not name this system | NVIDIA InfiniBand HDR · counts: 4 |
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
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.