12'000 years of computation

At the close of a tight competition, plasma simulation projects implying CRPP physicists obtained a significant part of the computation time on the Helios computer. Indeed, no less than 19.5 % of the total computation time, i.e. 111 millions core-hours were allotted to their projects, whereas the total of the submitted requests represented 3.6 times the available computation time.

The projects that involve the CRPP as principal or joint proposer are mainly linked to studies of a phenomenon having a fundamental influence on the performances of a fusion reactor: the turbulence that appears spontaneously in very high temperature plasmas. Projects on modelling of materials for fusion can also count on an important computation time.

Helios is a massively parallel supercomputer, located in Japan, devoted entirely to magnetic fusion research in Europe and Japan. It is one of the most powerful platforms in the world, with a peak performance of 1.5 PetaFlops (1.5 millions of billions of operations per second), ranking no 12 in the TOP500 list. It has 70 560 cores or processors. One core-hour corresponds to one hour of computation performed with 1 processor. That is precisely what a "massively parallel" computer allows to do: to perform calculations simultaneously on several processors and to drastically diminish the time needed to get to a result. 12 000 years come down to about 2 months…