no parallel speedup with slepc krylovschur

Christian May cmay at
Tue Jun 30 06:48:49 CDT 2009

Dear readers,

I want to solve the following generalized eigenvalue problem in parallel:
(gnu zipped tar of the binaryoutput you get using -eps_view_binary)

I know the approximate value of the lowest eigenvalues I'm interested in, 
so I'm using shift-and-invert with the following options:

-eps_type krylovschur -st_type sinvert -st_shift -0.228 -eps_ncv 32 
-eps_nev 16 -eps_tol 1e-10

However, when I use multiple CPUs, I cannot see any speedup. I am not sure 
whether this is a problem of the matrix or of my system. Can anybody 
please have a look?


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