# Swiss National Supercomputing Centre

The Swiss National Supercomputing Centre (Italian: Centro Svizzero di Calcolo Scientifico; CSCS) is the national high-performance computing centre of Switzerland. It was founded in Manno, canton Ticino, in 1991. In March 2012, the CSCS moved to its new location in Lugano-Cornaredo.
The main function of the Swiss National Supercomputing Centre is a so-called National User Lab. It is open to all Swiss researchers and their assistants, who can get free access to CSCS' supercomputers in a competitive scientific evaluation process.
In addition, the centre operates dedicated computing facilities for specific research projects and national mandates, e.g. weather forecasting. It is the national competence centre for high-performance computing and serves as a technology platform for Swiss research in computational science.
CSCS is an autonomous unit of the Swiss Federal Institute of Technology in Zurich (ETH Zurich) and closely collaborates with the local University of Lugano (USI).

## Building

The building at the new location Lugano-Cornaredo has a pillar-free machine hall of 2,000 m$^2$ and can be powered with up to 20 MW electricity. Water for cooling the supercomputers is taken from Lake Lugano in 45m depth and pumped over a distance of 2.8 km to the centre. Thus, little energy is consumed for providing the cooling and the computer centre achieves a high energy efficiency with a PUE < 1.25.

## Supercomputers

Supercomputer procurements at CSCS can be categorised into two phases: In the first phase from 1991 to 2011, the centre focused on proven technologies in order to facilitate user access to its services. This strategy was centred on the SX vector processor architecture of NEC. The IBM SP4, installed 2002, was the first production system of CSCS with a massively-parallel computer architecture. The procurement of the first Cray XT3 in Europe in 2005 marked the beginning of the second phase. Since then, CSCS concentrates on early technologies, preferably before they become a generally available product.

### Current computing facilities

| Name | Model | Processor type | No. of processors | Start of operation (last upgrade) | Peak performance (FLOPS) | Use |
| Piz Daint | Hybrid Cray XC40/XC50 | Intel Haswell-EP + Nvidia Tesla P100 GPUs | 206,720 cores | 2017 | 29.347 petaflops | Research (computer simulations) |
| Arolla and Tsa | Cray CS-Storm | Intel Xeon Gold 6134 + Nvidia Tesla V100 GPUs | | | | Numerical weather prediction (MeteoSwiss) |
| Mönch | NEC cluster | | | | | |
| Monte Leone | HP DL 360 Gen 9 | | | | | |
| Phoenix | Computer cluster (various manufacturers) | Intel Sandy Bridge 2.6 GHz and AMD Opteron 16-core Interlagos 2.1 GHz | 82 (736 cores) | October 2007 (May 2012) | 13.32 teraflops | Computing grid of the CERN LHC |

### Previous computing facilities

| Name | Model | Processor type | No. of processors | Period of operation | Peak performance (TFLOPS) | Use |
| Kesch and Es-cha | Cray CS-Storm | Intel Haswell-EP + Nvidia Tesla K80 GPUs | | 2015–2020 | | Numerical weather prediction (MeteoSwiss) |
| Piz Daint | Hybrid Cray XC30 | Intel Sandy Bridge 2.6 GHz + NVIDIA Tesla K20X GPUs | 5,272 (42,176 cores; 84,352 hardware threads + 1 GPU x node) | November 2013 | 7,787 | Research (computer simulations) |
| Blue Brain 4 | IBM Blue Gene/Q | Power BQC 16C 1.6 GHz | 65,536 cores | 2013–2018 | 838.9 | Blue Brain Project |
| Piz Daint | Cray XC30 | Intel Sandy Bridge 2.6 GHz | 4,512 (36,096 cores; 72,192 hardware threads) | December 2012 | 750.7 | Research (computer simulations) |
| Monte Lema | Cray XE6 | AMD Opteron 12-core Magny-Cours 2.1 GHz | 336 (4,032 cores) | April 2012 | 33.87 | Numerical weather prediction (MeteoSwiss) |
| Albis | Cray XE6 | AMD Opteron 12-core Magny-Cours 2.1 GHz | 144 (1,728 cores) | April 2012 | 14.52 | Numerical weather prediction (MeteoSwiss) |
| Tödi | Cray XK7 | AMD Opteron 16-core Interlagos 2.1 GHz and Nvidia Tesla K20x GPU | 272 (4,352 cores) + 272 GPUs | October 2011 (October 2012) | 393.00 | Research (computer simulations) |
| Matterhorn | Cray XMT Next Generation | Cray Threadstorm | 64 (8,192 hardware threads) | June 2011 | n/a | Research (in particular analysis of unstructured data) |
| Monte Rosa | Cray XE6 | AMD Opteron 16-core Interlagos 2.1 GHz | 2,992 (47,872 cores) | May 2009 (November 2011) | 402.12 | Research (computer simulations) |
| La Dôle | Cray XT4 | AMD Opteron quad-core Barcelona 2.3 GHz | 160 (640 cores) | May 2007–June 2012 | 5.88 | Numerical weather prediction (MeteoSwiss) |
| Piz Buin | Cray XT4 | AMD Opteron quad-core Barcelona 2.3 GHz | 264 (1,056 cores) | May 2007–June 2012 | 9.71 | Numerical weather prediction (MeteoSwiss) |
| Mont Blanc | IBM System p575 | IBM POWER5, 1.5 GHz | 768 | October 2006–January 2010 | 4.6 | Research (computer simulations) |
| Piz Palü | Cray XT3 | AMD Opteron dual-core 2.6 GHz | 1,664 (3,328 cores) | June 2005–April 2009 | 17.31 | Research (computer simulations) |
| Venus | IBM System p690 | IBM POWER4, 1.3 GHz | 256 | 2002–2006 | 1.33 | Research (computer simulations) |
| Prometeo | NEC SX-5 | NEC SX-5 vector processor | 16 | 1999–2007 | 0.128 | Research (computer simulations) and numerical weather prediction (MeteoSwiss) |
| Gottardo | NEC SX-4 | NEC SX-4 vector processor | 16 | 1995–2004 | 0.032 | Research (computer simulations) |
| Adula | NEC SX-3 | NEC SX-3 vector processor | 2 | 1992–1995 | 0.0128 | Research (computer simulations) |

## National Supercomputing Service

Run as a user lab, CSCS promotes and encourages top-notch research. Simulations created on supercomputers yield completely new insights in science. Consequently, CSCS operates cutting-edge computer systems as an essential service facility for Swiss researchers. These computers aid scientists with diverse issues and requirements - from the pure calculation of complex problems to analysis of complex data. The pool of national high-performance computers is available to its users as a so-called user lab: all researchers in and out of Switzerland can use the supercomputer infrastructure.

## Dedicated HPC Services

In addition to the computers of the User Lab, CSCS operates dedicated compute resources for strategic research projects and tasks of national interest. Since 2001, the calculations for the numerical weather prediction of the Swiss meteorological survey MeteoSwiss take place at the Swiss National Supercomputing Centre. In January 2008, the first operational high-resolution weather forecasting suite in Europe was taken in production on a massively-parallel supercomputer at CSCS. Another dedicated computer resource operated by CSCS is the Swiss tier-2 computer cluster for the Computing Grid of the CERN LHC accelerator.
CSCS also provides storage services for massive data sets of the Swiss systems biology initiative SystemsX and the Centre for Climate Systems Modelling C2SM at ETH Zurich.

## Research and development

For supporting the further development of its supercomputing services, CSCS regularly evaluates relevant new technologies (technology scouting) and publishes the results as white papers on its website.
In 2009, CSCS and the University of Lugano jointly launched the platform HP2C with the goal to prepare the application codes of Swiss researchers for upcoming supercomputer architectures.