Impacts of Current Hardware and Software Developments on Simulation Sciences

For more than a decade single compute core performance is no longer doubling every 18-24months. Physical limitations due to successive chip miniaturisation are visible and it becomesincreasingly difficult to dissipate the heat being generated by tiny high-clocked and denselypacked compute cores. To circumvent these limitations massive parallelism has been introduced:more and more processors – each of them equipped with an increasing number of moderatelyclocked compute cores – are assembled in big systems to reach highest performance. Moreover,accelerators like general-purpose graphical processing units (GP-GPUs), field programmablegate arrays (FPGAs) or Intel’s Many Integrated Core (MIC) architectures are increasingly usedto further boost the application performance.These developments have a serious impact on applications which partly have a history of severaldecades. Application codes can only benefit from the new architectures if they are optimizedwith respect to massive parallelism and the incorporation of accelerators. Application scientistsand experts in high-performance computing (HPC) therefore have to make common efforts tomaster this challenge. Additionally, a much closer collaboration between hardware architects andcomputational scientists has to be established to make them mutually aware of hardware andsoftware issues and to enable robust solutions to be developed jointly.In the presentation current hardware and software developments will be introduced. By means ofseveral activities of the Juelich Supercomputing Centre it will be demonstrated how a computercentre can support and guide its users towards new technology, how new technology can beinfluenced by user demands, how hardware developments trigger new software developmentsand finally, how the successful exploitation of these technical advances leads to new scientificinsights