On 02/28/2016 10:27 AM, Jon Tegner wrote:
Hi,
have issues with performance on E5-2680. Each of the nodes have 2 of
these 12 core CPUs on SuperMicro SuperServer 1028R-WMR (i.e., 24 cores
on each node).
For one of our applications (CFD/OpenFOAM) we have noticed that the
calculation runs faster using 12 cores on 4 nodes compared to when
using 24 cores on 4 nodes.
In our environment we also have older AMD hardware (nodes with 4 CPUs
with 12 cores each), and here we don't see these strange scaling issues.
System is CentOS-7, and communication is over FDR Infiniband. BIOS is
recently updated, and hyperthreading is disabled.
Feel a bit lost here, and any hints on how to proceed with this are
greatly appreciated!
Need lots more info. What does
numastat
report for example? Are you running openfoam in a way to enforce
affinity? Do you have hugepages enabled/disabled? Is openfoam using
RDMA or do you have it running IPoIB?
Thanks,
/jon
_______________________________________________
Beowulf mailing list, [email protected] sponsored by Penguin Computing
To change your subscription (digest mode or unsubscribe) visit
http://www.beowulf.org/mailman/listinfo/beowulf
--
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
e: [email protected]
w: http://scalableinformatics.com
t: @scalableinfo
p: +1 734 786 8423 x121
c: +1 734 612 4615
_______________________________________________
Beowulf mailing list, [email protected] sponsored by Penguin Computing
To change your subscription (digest mode or unsubscribe) visit
http://www.beowulf.org/mailman/listinfo/beowulf
