Supercomputers/Systems/Piz Daint
Switzerland · decommissioned · mixed
Piz Daint
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: 32 of 52 systems have a readable citation that names them, and 4 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
- 21.23 PFlop/s
- Rpeak
- 27.15 PFlop/s
- Rmax ÷ Rpeak
- 78.2%
- Cores
- 387,872
- Power
- 2.38 MW
- Per watt
- 8.9 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 | - Cray XC50 | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | cscs.chhpe.com |
| Accelerator | NVIDIA Tesla P100 Accelerators NVIDIA Tesla P100 | NVIDIA | - | Reported | cscs.chhpe.com |
| CPU | Intel Xeon E5-2690 v3 CPUs Xeon E5-2690v3 12C 2.6GHz | Intel | - | Reported | cscs.chhpe.com |
| Interconnect | Cray Aries Interconnect Aries interconnect | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | cscs.chhpe.com |
| Cooling | Liquid-assisted air (in-cabinet coil) Cooling Cray XC50 cabinet: transverse air across in-cabinet water coils | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | cscs.chhpe.com |
| Operating system | Cray Linux Environment Operating systems Cray Linux Environment | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | cscs.chhpe.com |
The read
Europe's fastest system for several years, and the direct predecessor of Alps on the same site. Cray XC50 with one P100 per node; the site retained the building, the lake-water cooling and the operator, and replaced everything else - which is what a refresh cycle actually looks like at the facility layer.
Timeline
- 2012 Announced source
- 2017-06 List debut at #3 (June 2017) source
- 2017-06 First operational source
- 2023 Decommissioned 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
CSCS, Lugano
- Location
- Lugano, Switzerland
- Cooling
- Lake-water cooling (Lake Lugano)
- Commissioned
- 2012
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.
One cited source was readable and does not mention this system; another could not be read because the host returned a bot challenge. The unreadable one may well be fine, so this is weaker evidence than a corroborated row and much stronger than an unsupported one. See how this check works.
Checked 2026-09-08 by pnpm verify. Re-run it and the table changes with the web.
Further reading
Inside a node
Why accelerators exist, what the memory hierarchy costs, and how the CPU and accelerator merged onto one package.
Power and cooling
Why air ran out at 20 kW a rack, how warm-water cooling removes the chillers, and what PUE conceals.
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.