title: Analysis of Inter-Chip Communication Patterns on Multi-Core Distributed Shared-Memory Computers creator: Mücke, Manfred creator: Gansterer, Wilfried N. subject: 004 subject: 004 Data processing Computer science description: Multi-core multi-socket distributed shared-memory com- puters (DSM computers, for short) have become an impor- tant node architecture in scientific computing as they provide substantial computational capacity with relatively low space and power requirements. Compared to conventional computer networks, inter-chip networks used in DSM computers feature higher bandwidth, lower latency and tighter integration with the CPU. The inter-chip network is a shared resource among the user application and many other services, which can lead to consid- erable variation of execution times of identical communication tasks. In this work, we explore traffic patterns resulting from MPI collective communication primitives and investigate the ques- tion whether inter-chip link load is a reliable indicator and predictor for the execution time of collective communication primitives on a DSM computer. Our experiments on a Sun Fire X4600 M2 DSM computer with 32 cores (eight quad-core CPUs) indicate that specific single link loads are positively correlated with the execution time of MPI ALLREDUCE. Ob- serving patterns over multiple links allows refinement of the single-link observation. date: 2011 type: Article type: info:eu-repo/semantics/article type: NonPeerReviewed format: application/pdf identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/11585/1/WHTRA2011_paper01.pdf identifier: DOI:10.11588/heidok.00011585 identifier: urn:nbn:de:bsz:16-opus-115852 identifier: Mücke, Manfred ; Gansterer, Wilfried N. (2011) Analysis of Inter-Chip Communication Patterns on Multi-Core Distributed Shared-Memory Computers. relation: https://archiv.ub.uni-heidelberg.de/volltextserver/11585/ rights: info:eu-repo/semantics/openAccess rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html language: eng