The bulk of our compute nodes are 8 cores (twin 4-core IBM x3550-m2). Jobs are submitted by Torque/MOAB. When run with up to np=8 there is good performance. Attempting to run with more processors brings problems, specifically if any one node of a group of nodes has all 8 cores in use the job hangs. For instance running with 14 cores (7+7) is fine, but running with 16 (8+8) hangs.
>From the FAQs I note the issues of over committing and aggressive scheduling. Is it possible for mpirun (or orted on the remote nodes) to be blocked from progressing by a fully committed node? We have a few x3755-m2 machines with 16 cores, and we have detected a similar issue with 16+16. Martin Rushton HPC System Manager, Weapons Technologies Tel: 01959 514777, Mobile: 07939 219057 email: jmrush...@qinetiq.com www.QinetiQ.com QinetiQ - Delivering customer-focused solutions Please consider the environment before printing this email. This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error. QinetiQ may monitor email traffic data and also the content of email for the purposes of security. QinetiQ Limited (Registered in England & Wales: Company Number: 3796233) Registered office: Cody Technology Park, Ively Road, Farnborough, Hampshire, GU14 0LX http://www.qinetiq.com.
