ETH's Jubilee wave reached southern point of Canton Tessin the weekend before last: the Centro Svizzero di Calcolo Scientifico (CSCS) (1) in Manno opened its doors to the public and showed visitors what it looks like inside a supercomputing centre. CSCS workers were very pleased that so many people were attracted to visit the industrial zone of Manno, despite the beautiful day outside, in finding out more about the work carried out at the CSCS.

Inconspicuous power

It was probably an insight into an unknown world for most visitors–and a remarkably understated one that they encountered on their tour around the centre. The speedy supercomputers, it must be said, look rather unassuming on the outside. The IBM pSeries 690 Turbo, for example, is a simple assembly of black lockers and even the massive NEC SX-5 was hardly impressive in its appearance. The only thing that indicated the sheer capacity of the invisible computing operations being carried out inside was the clearly audible hum of the air conditioning.

The problems that are handled using these machines are, quite literally, manifold. Climatologists, geologists, engineers, material scientists, biochemists and particle physicists make up the main clientele of the CSCS. Federal offices and (federal) institutions, such as the National Alarm Control Centre and the meteorological service, MeteoSchweiz, use the computer in Manno.

Balanced architecture

Supercomputers are judged first and foremost on the computing power of their processors. As Djordje Maric, Chief Technology Officer at CSCS, explained, however, this isn't the most decisive criterion. "In order for the computing power to be used in an optimal way, it needs a balanced architecture. It's important, for instance, that data can be transferred back and forward between the main storage and the processors as rapidly as possible." An effective internet connection was also a decisive factor.

"But there isn't simply one kind of architecture that's right," added Maric, "because not every computer is suitable for all applications". People who run computing centres are faced with a certain dilemma. In order to carry out the wide range of tasks on hand in an optimal way, one aimed to use as many different computer systems as possible. The client, on the other hand, was more interested in the simplest possible interface. "To the outside we therefore have to conceal the heterogeneity of the hardware as far as we can."

Strength of the centre

That Switzerland will also need a super computing centre in future is something of which Marie-Christine Sawley, CEO des CSCS (2), is convinced. True, individual groups of researchers had built computers off their own bat for relatively small sums, and indeed on paper these machines needn't shy comparison with expensive supercomputers, like those used in Manno. Such own constructions, however, can also be very tricky. "It takes a lot of know-how to run and manage a supercomputer", says Sawley. "Individual groups simply don't have the resources in the long run." In addition it was often not possible to employ these computers in other fields of research.

"A computing centre like CSCS works with long-term orientation and this is precisely what is paramount in certain areas of research." There was very close collaboration, for example, between CSCS and CERN in Geneva. "Particle physicists process certain data with us," said Marie-Christine Sawley. "At the same time, we have a very large storage capacity, where physicists can store their colossal amounts of data."

Back in the top 100

In Manno people are very proud of one of their computers, of which visitors only got to see a small part. In a room that is still half empty the new Cray XT-3 (3) will be installed by the end of June. "With this computer we will be able to simulate certain problems in even more detail," explains Dominik Ulmer, Chief Operating Officer at CSCS. With the Cray XT-3, CSCS will again be under the top 100 list of the world's fastest 500 supercomputers (4). "Of course it's great to have a high place on this list," said Sawley. "But for us it's not only the processing speed that counts but, above all, that the scientific quality of the output is accurate."

Although the new computer is not yet operative, computer scientists at Manno are already busy with the next step. It will soon be necessary to replace the NEC SX-5. MeteoSchweiz, which uses this computer twice daily for its weather forecasts, would like to use more precise models in future that would enable them, for instance, to predict the occurrence of Föhn situations (a warm wind, specific to Switzerland). Carrying out a single simulation every twelve hours would no longer suffice for this. Meteorologists would like to book the computer in Manno at fixed times eight times a day, something that presents the people running the centre with something of a problem. "The question is whether the time in between can still be used efficiently," explains Ulmer. "This is a great challenge for CCS, but one that we are pleased to take on."