Slovenian National Supercomputing Network

What is HPC?

The acronym HPC could be creatively translated as Hyperactive Process Circus. An example of such a system, the Arctur-2 from Nova Gorica, is pictured right. It is an above-average-performance computing system that works at full capacity for most of its lifetime – so we can say that compared to the sloths known as desktop computers, it is a true hyperactive system. We will come back to this comparison, but first let us resolve the rest of the meaning of the acronym HPC. It is about processing, that is to say, computing. We can perform or compute more calculations more quickly on such a system than on conventional computers, which is why some people call it a supercomputer. Last but not least, we can see in the picture that the computer is round, which immediately reminds us of a circus. It is also at least as noisy as a circus – both in terms of sound and media. And every modern country wants to have its own circus, as big as possible and with as many lights as possible. Slovenia too.

Arctur Open Day

Incidentally, most of the processing power in today’s supercomputers comes from massively parallel graphics accelerators, which are designed to accelerate computation in a wide variety of applications (least of all graphics). The above image of HPC Vega shows a room with cabinets containing compute nodes. The keen observer will note that this supercomputer is not in a circular layout – the reason is probably the space utilisation, which is slightly worse in a circular layout. The picture on the left shows a detail of one compute node with a dozen AMD Epyc 7H12 processors.

The nodes are like drawers that you stack in a cupboard. HPC Vega has 12 cabinets of drawers with compute nodes.

It helps both the cooling and the pulling of the cables if the supercomputer is placed in a circle

This was a successful trick by Cray Research, which built one of the best-selling supercomputers, the Cray-1, in 1976. They sold about 80 of them. The C-shaped layout allowed them to have shorter connections between nodes and thus shorter latency times. As a result, the processor hour frequency could be faster, which meant higher performance. It was succeeded in 1985 by the Cray-2, the fastest supercomputer of the time. It was used, among other things, to simulate car crashes and thus improve the mechanical properties of the bodywork. By comparison, 26 years later, the Cray-2’s computing power was matched by the iPad2.