The Hen is mightier than the Hornet
The second upgrade of the supercomputer at Stuttgart’s High Performance Computing Centre (HLRS) has been completed. The Cray XC40 system at HLRS – code-named ‘Hazel Hen’ – delivers a peak performance of 7.42 Petaflops, almost twice as much as the previous system -- known as Hornet. Hazel Hen marks the final stage in the machine’s expansion, as defined in HLRS’s system roadmap, and it is now officially available to support scientific and industrial users both nationally within Germany and on a European scale also.
Hazel Hen uses Cray’s Aries interconnect technology and the Dragonfly network topology. The installation has 41 system cabinets hosting 7,712 compute notes with a total of 185,088 Intel Haswell E5-2680 v3 compute cores. Main memory is 965 Terabytes and there is a total of 11 Petabyte of storage capacity spread over 32 additional cabinets hosting more than 8,300 disk drives which can be accessed at a rate of more than 350 Gigabyte per second.
Before the official statement that the system was operational, HLRS allowed access to some users for beta testing. Researchers from the Institute of Aerodynamics (AIA) at the RWTH Aachen University used it to study ways of reducing the emissions of CO2 from conventional coal-fired power plants through oxy-fuel combustion. By simulating the heating processes of coal dust, the scientists aimed at gaining a better understanding about the conditions causing the carbon dust to ignite in an oxygen-carbon dioxide atmosphere. Such calculations are extremely complex since carbon particles are of irregular, non-spherical shape, so their motion is difficult to predict. Hazel Hen ran simulations of thousands of fully dissolved carbon particles moving freely in a turbulent flow. Principal investigator Dr Matthias Meinke of the AIA said: ‘Thanks to the computing capacities offered by Hazel Hen, we are able to execute calculations with particle numbers of a magnitude that up to now would have required several individual simulation steps.’
Researchers from the Karlsruhe Institute for Technology (KIT) and the Institute of Materials and Processes (IMP) of the Karlsruhe University of Applied Sciences used the computing capacity of Hazel Hen for numerical simulations of solidification processes using the phase-field method. They simulated the ternary eutectic directional solidification of Al-Ag-Cu (Aluminium-Silver-Copper) in an area of 4116 x 4008 x 1000 cells to study the resulting patterns and the 3D-development of the micro structure. Ternary super-alloys with defined properties for high-performance materials are of growing importance in the aerospace industry. A solid understanding of the material and process parameters of the solidifying process is thus indispensable.
Professor Michael Resch, Director of the HLRS, said: ‘With Hazel Hen, we again are in the favourable position of being able to offer our users a state-of-the-art HPC system that meets their requirements. The first user projects already did deliver outstanding results and we are confident for Hazel Hen to achieve further simulation highlights in the future.’
With the installation of Hazel Hen, HLRS completed the last step of its system roadmap as defined with the current purchasing plan by the German Federal Ministry of Education and Research and the federal states of Baden-Württemberg, Bavaria, and North Rhine-Westphalia. This purchasing plan specified the step-by-step installation and expansion of Tier-0 HPC systems at the three national German high-performance computing centres in Stuttgart (HLRS), Garching near Munich (Leibniz Supercomputing Centre/LRZ) and in Jülich (Jülich Supercomputing Centre/JSC) to ensure Germany’s competitiveness in the global HPC arena.