On Fri, 22 Apr 2011 19:32:00 -0400, Boshen Gao <[email protected]> wrote: > Hi all, > I am using meep-mpi to simulate some simple 3-D SOI photonic crystal based > structures on my PC. It has an i7-930 Quad-core CPU @ 4 GHz. My problem is, > while I use command > > mpirun -np 4 meep-mpi *****.ctl > > each core will run the code alone, they do not share the work. So each step > will be run four times, a code that took 90 sec on one core now takes more > than 100 sec using all four cores. Now I'm running resolution 32 codes that > takes more than 30 hours. In this case, parallel computation will be of > great help. Has anyone met similar problems or do you have any hints on > what > might go wrong, please? > > Thank you. > > Boshen Gao
Hi, it happened to me too time ago and as far as I can recall in my csae it was because I had first installed openmpi, then the ubuntu package for meep-mpi which was (the version that I installed, I did not check for the present version) based on MPICH2 and I guess the two different MPI programs interfered with each other somehow. I solved my problem by 1) uninstalling both openmpi and meep-mpi 2) reinstalling openmpi 3) compiling meep-mpi from source (as I wanted to use openmpi, which I read somewhere is a little better for multi-core, I may be wrong though). You may check whether this is the case for you too. Cheers, Giovanni -- ================================================ Giovanni Piredda Postdoc - AK Hartschuh Phone: ++49 - (0) 89/2180-77601 Fax.: ++49 – (0) 89/2180-77188 Room: E2.062 ---------------------------------------- Message sent by Cup Webmail (Roundcube) _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
