Supercomputers/Systems/Blue Brain IV
Switzerland · decommissioned · hpc
Blue Brain IV
Also known as EPFL Blue Brain IV
Operated by CSCS at CSCS, Lugano .
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
- 715.55 TFlop/s
- Rpeak
- 838.86 TFlop/s
- Rmax ÷ Rpeak
- 85.3%
- Cores
- 65,536
- Power
- 328.75 kW
- Per watt
- 2.2 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 Blue Gene/Q, four racks | IBM | - | Verified | top500.orgcscs.ch |
| CPU | IBM PowerPC A2 (Power BQC) CPUs PowerPC A2 · 18C · 1.6 GHz · 45 nm · 55 W Power BQC 16C 1.6GHz (PowerPC A2), 65,536 cores | IBM | - | Verified | top500.orgcscs.ch |
| Interconnect | IBM BlueGene/Q 5D torus Interconnect 5D torus · 2 GB/s per link per direction Custom Blue Gene/Q interconnect | IBM | - | Reported | top500.org |
The read
Four-rack IBM Blue Gene/Q bought by EPFL's Blue Brain Project and hosted at CSCS in Lugano, 48th on the November 2013 TOP500 and used for neuron-network simulation. TOP500 and CSCS agree on 65,536 Power BQC / PowerPC A2 1.6 GHz cores; TOP500 gives 715.55 TFlop/s Rmax and 838.86 TFlop/s Peak, CSCS quotes 839 TFlop/s peak, 65 TB of RAM and 128 TB of BlueGene Active Storage, and lists the machine in its decommissioned section. TOP500 last lists it in June 2018; no shutdown date is recorded.
Timeline
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Site & facility
CSCS, Lugano
- Location
- Lugano, Switzerland
- Cooling
- Lake-water cooling (Lake Lugano)
- Commissioned
- 2012
Change history
- 2026-10-02 Added Blue Brain IV, CSCS Blue Gene/Q
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 |
|---|---|---|
| cscs.ch | names system and part | IBM PowerPC A2 (Power BQC), IBM BlueGene/Q 5D torus |
| top500.org | names system and part | IBM BlueGene/Q 5D torus |
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.