[mpich-discuss] multi threading

[Rajeev Thakur]

Are your programs multithreaded or are they just multiprocess MPI programs?
If the latter, don't use the --enable-threads=multiple option. Instead, use
the Nemesis communication device by configuring with
--with-device=ch3:nemesis.
 
Rajeev
 


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From: owner-mpich-discuss at mcs.anl.gov
[mailto:owner-mpich-discuss at mcs.anl.gov] On Behalf Of David R Anderson
Sent: Friday, April 18, 2008 9:10 AM
To: mpich-discuss at mcs.anl.gov
Subject: [mpich-discuss] multi threading



I have mpich2 (1.0.6) installed on a Dell poweredge compute server with Red
Hat Linux installed.  The server is new and has 4-quad core processors.  I
have compiled mpich2 using the --enable-threads=multiple option for
configure.   After compiling mpi versions of several programs I find that I
get good speedup results up to 8 processors, however, no benefit from 9-16.
There is a small drop in performance from 8-9 and then by 16 processors has
caught back up to the same speedup value as with 8. 

Is there something else I need in the config options, or is dual threading
the best that I can get?  I'd appreciate any advice. 

Thanks in advance, 

Dave 
---------------------------------------------------
David R. Anderson
Principal Engineer
D412, Radiation Analysis Section
Phone: (860)433-6584, FAX (860)433-3229
E-mail: danders3 at gdeb.com


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