Ikki Fujiwara

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—As the scales of supercomputers increase total cable length becomes enormous, e.g., up to thousands of kilometers. Recent high-radix switches with dozens of ports make switch layout and system packaging more complex. In this study, we study the optimization of the physical layout of topologies of switches on a machine room floor with the goal of reducing(More)
—As the scales of parallel applications and platforms increase the negative impact of communication latencies on performance becomes large. Random network topologies can be used to achieve low hop counts between nodes and thus low latency. However, random topologies lead to increased aggregate cable length and cable packaging complexity on a machine room(More)
— Network bandwidth is a performance concern especially for collective communication because the bisection bandwidth of recent supercomputers is far less than their full bisection bandwidth. In this context we propose to exploit the use of a network coding technique to reduce the number of unicasts and the size of transferred data generated by(More)
—In this paper, we demonstrate that we can reduce the communication latency significantly by inserting a fraction of randomness into a wireless 3D NoC (where CMOS wireless links are used for vertical inter-chip communication) when considering the physical constraints of the 3D design space. Towards this end, we consider two cases, namely 1) replacing(More)
—Low communication latency becomes a main concern in highly parallel computers and supercomputers. Random network topologies are best to achieve low average shortest path length and low diameter in hop counts between nodes and thus low communication latency. However, random topologies lead to a problem of increased aggregate cable length on a machine room(More)
—Random network topologies have been proposed to create low-diameter, low-latency interconnection networks in large-scale computing systems. However, these topologies are difficult to deploy in practice, especially when redesigning existing systems, because they lead to increased total cable length and cable packaging complexity. In this work we propose a(More)