Are nonblocking networks really needed for high-end-computing workloads?

—High-speed interconnects are frequently used to provide scalable communication on increasingly large high-end computing systems. Often, these networks are nonblocking, where there exist independent paths between all pairs of nodes in the system allowing for simultaneous communication with zero network contention. This performance, however, comes at a heavy cost as the number of components needed (and hence cost) increases superlinearly with the number of nodes in the system. In this paper, we study the behavior of real and synthetic supercomputer workloads to understand the impact of the network’s nonblocking capability on overall performance. Starting from a fully nonblocking network, we begin by assessing the worse-case performance degradation caused by removing interstage communication links, resulting in overprovisioning and hence potentially blocking in the communication network. We also study the impact of several factors on this behavior, including system workloads, multico...

• Type: Conference
• Year: 2008
• Where: CLUSTER
• Authors: Narayan Desai, Pavan Balaji, P. Sadayappan, Mohammad Islam
• Keywords: CLUSTER 2008, Cluster Computing, Communication, Network’s Nonblocking Capability, Synthetic Supercomputer Workloads