Supercomputers/Systems/Stella
Netherlands · decommissioned · hpc
Stella
Also known as LOFAR central processor; ASTRON/University Groningen Blue Gene/L
Operated by University of Groningen .
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
- 27.45 TFlop/s
- Rpeak
- 34.41 TFlop/s
- Rmax ÷ Rpeak
- 79.8%
- Cores
- 12,288
- Power
- 134 kW
- Per watt
- 0.2 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 | - IBM eServer Blue Gene Solution, six racks | IBM | - | Reported | top500.orgastro.rug.nl |
| CPU | IBM PowerPC 440 700MHz CPUs PowerPC · 2C · 0.7 GHz · 130 nm · 13 W PowerPC 440 dual-core 700 MHz, 6,144 chips | IBM | - | Reported | top500.orgcomputable.nl |
| Interconnect | IBM BlueGene 3D torus Interconnect 3D torus, plus separate collective and barrier networks · 175 MB/s per link per direction Blue Gene proprietary interconnect | IBM | - | Reported | top500.org |
The read
An IBM Blue Gene/L of six racks and 6,144 dual-core 700 MHz PowerPC 440 chips at the University of Groningen computing centre, named Stella for its job as the central processor of the LOFAR radio telescope. The Kapteyn Institute's 2005 annual report records the Dutch education minister dedicating the machine in April 2005 and revealing the name. A June 2005 Computable report put it at 27.4 TFLOPS and fourth in the world. TOP500 lists it sixth on the June 2005 list at 27.45 TFLOPS Rmax and 34.41 peak, drawing 134 kW, and credits ASTRON and the University of Groningen. No retirement date was found in the pages we cited, and the TOP500 entry is the only source for Rmax, so the tier is reported.
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
- 2026-10-02 Added Stella, the Groningen Blue Gene/L for LOFAR
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 |
|---|---|---|
| top500.org | names system and part | IBM PowerPC 440 700MHz |
| astro.rug.nl | does not name this system | - |
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.