no parallel speedup with slepc krylovschur

Toby D. Young tyoung at
Tue Jun 30 09:46:29 CDT 2009

> Sure, here's the output for 2 CPUs:
> **************
> Job <ompirun ./SPsolver3D-dune ini-files/fuhrer-dot/fuhrer-dot-test.ini
> -eps_type krylovschur -st_type sinvert -st_shift -0.228 -eps_ncv 32
> -eps_tol 1
> e-10 -ksp_monitor -ksp_type gmres -pc_type bjacobi -ksp_rtol 1e-14
> -st_ksp_rtol 1e-14 -ksp_converged_reason> was submitted from host
> <brutus2> by user
>   <cmay>.
> Job was executed on host(s) <2*a6400>, in queue <beta.m>, as user <cmay>.
> </cluster/home/phys/cmay> was used as the home directory.
> </cluster/home/phys/cmay/SPsolver3D> was used as the working directory.
> Started at Tue Jun 30 15:32:25 2009
> Results reported at Tue Jun 30 15:49:58 2009

Something is not right here.....

I think you are using SLEPc incorrectly. I suspect that you are not taking
advantage of the MPI process or the solvers in an efficient way.

How does your code scale with other solvers?

My advice: Talk to the SLEPc guys!   :-)

Sorry I can be of no more help; but I will look at your code tomorrow and
report anything if something.



Toby D. Young
Adiunkt (Assistant Professor)
Polish Academy of Sciences
Warszawa, Polska

skype: stenografia

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