[Beowulf] WRF model on linux cluster: Mpi problem

[federico.ceccarelli]

Hi!

I would like to get in touch with people running numerical meteorological
models  on a linux cluster (16cpu) , distributed memory (1Gb every node),
diskless nodes, Gigabit lan, mpich and openmosix.

I'm tring to run WRF model but the mpi version parallelized on 4, 8, or 16
nodes runs slower than the single node one! It runs correctly but so slow...

When I run wrf.exe on a single processor the cpu time for every timestep is
about 10s for my configuration.

When I switch to np=4, 8 or 16 the cpu time for a single step sometimes its
faster (as It should always be, for example 3sec for 4 cpu ) but often it is
slower and slower (60sec and more!). The overall time of the simulation is
bigger than for the single node run...

anyone have experienced the same problem?

thanks in advance to everybody...

federico



Dr. Federico Ceccarelli (PhD)
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