A supercomputer ranking published on 19 June 2017, places Switzerland’s 19.6 petaflop1 Piz Daint supercomputer third in the world after Sunway TaihuLight and Tianhe 2, two Chinese supercomputers. Piz Daint’s recent upgrades allowed it to climb five positions up the ranking.
With a performance of 93 petaflops1, China’s TaihuLight is by far the most powerful number-cruncher on the planet. Tianhe-2, which translates to Milky Way-2, comes in second at 33.9 petaflops1, losing its number one spot in June 2016.
The Piz Daint computer, run by the Swiss National Supercomputing Centre (CSCS) is located the commune of Lugano. Named after a peak in the Alps, it is the most powerful computer in Europe. The monster computer is used by Switzerland’s weather service for climate modelling, the Swiss Institute of Particle Physics, the Human Brain Project and numerous others.
CSCS was created in 1985 after the Swiss government decided the country needed to invest in computing.
The CSCS computing centre uses as much electricity every day as a small town. About a third of this electricity is used for cooling – computers get hot and must be cooled otherwise they melt. Piz Daint is cooled with up to 760 litres of water per second from nearby Lake Lugano. Using cool water from the lake significantly reduces overall electricity consumption. The water, taken 45m down is around 6 degrees. For ecological reasons, the water returning to the lake must never be over 25 degrees.
This is the first time since 1996, when three Japanese supercomputers captured the top three spots, that the United States has failed to secure a top-three position. The US still claims five of the top ten supercomputers, more than any other nation.
A flop is the number of computing operations (floating point) per second. One petaflop is 1015 flops. CSCS lists the Piz Daint hybrid Cray XC40/XC50 system‘s hybrid peak performance at 25.3 petaflops, whereas the ranking uses Linpack, a different measure, which gives it a performance rating of 19.3 petaflops1.