[petsc-users] Preconditioner for LSQR

[Lucas Banting]

Hello,

I have an MPIDENSE matrix of size about 200,000 x 200, using KSPLSQR on my machine a solution takes about 15 s. I typically run with six to eight processors.
I have to solve the system several times, typically 4-30, and was looking for recommendations on reusable preconditioners to use with KSPLSQR to increase speed.

Would it make the most sense to use PCCHOLESKY on the smaller system A^T * A?

Thanks,
Lucas
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