AW: NAMD SMP version warning - Reg

From: Norman Geist (
Date: Wed Jul 04 2018 - 05:12:46 CDT

If you have 32 cores, why requesting to start 128 workers then?


Von: [] Im Auftrag von Mani Kandan
Gesendet: Mittwoch, 4. Juli 2018 11:58
Betreff: namd-l: NAMD SMP version warning - Reg


Dear all,


             I am using NAMD 2.12 SMP (infiniband version), while running in my cluster it shows the following warning


Charm++> Running on 1 unique compute nodes (32-way SMP).
Charm++> cpu topology info is gathered in 0.069 seconds.

Charm++> Warning: the number of SMP threads (136) is greater than the number of physical cores (32), so threads will sleep while idling. Use +CmiSpinOnIdle or +CmiSleepOnIdle to control this directly.



                  How can i rectify this problem? and performance also very slow. I am using following command to run namd: charmrun ++mpiexec +p128 ++ppn 16 ++nodelist $LOADL_HOSTFILE namd2 <file>

I am having 16 cores per processor.


Kindly help me in these regard.



Manikandan D

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