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Preparing NERSC users for Cori , a Cray XC40 system with Intel many integrated cores
Author(s) -
He Yun,
Cook Brandon,
Deslippe Jack,
Friesen Brian,
Gerber Richard,
HartmanBaker Rebecca,
Koniges Alice,
Kurth Thorsten,
Leak Stephen,
Yang WooSun,
Zhao Zhengji,
Baron Eddie,
Hauschildt Peter
Publication year - 2017
Publication title -
concurrency and computation: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.309
H-Index - 67
eISSN - 1532-0634
pISSN - 1532-0626
DOI - 10.1002/cpe.4291
Subject(s) - computer science , operating system , xeon , xeon phi , supercomputer , vectorization (mathematics) , parallel computing
Summary The newest NERSC supercomputer Cori is a Cray XC40 system consisting of 2,388 Intel Xeon Haswell nodes and 9,688 Intel Xeon‐Phi “Knights Landing” (KNL) nodes. Compared to the Xeon‐based clusters NERSC users are familiar with, optimal performance on Cori requires consideration of KNL mode settings; process, thread, and memory affinity; fine‐grain parallelization; vectorization; and use of the high‐bandwidth MCDRAM memory. This paper describes our efforts preparing NERSC users for KNL through the NERSC Exascale Science Application Program, Web documentation, and user training. We discuss how we configured the Cori system for usability and productivity, addressing programming concerns, batch system configurations, and default KNL cluster and memory modes. System usage data, job completion analysis, programming and running jobs issues, and a few successful user stories on KNL are presented.