[petsc-users] comparing HYPRE on CPU vs GPU

[nicola varini]

Dear all, I am comparing the HYPRE boomeramg preconditioner on CPU and GPU.
It looks like the defaults are different, therefore I tried to specify the
match the options.
I have a few observations/questions:
1) Why are the residuals at step 0 different?
2) If the options are the same the number of iterations should be the same?
3) Why on the GPU side the PCApply doesn't seem to be done on GPU?
I noticed that if I change certain options, like
pc_hypre_boomeramg_relax_type_all symmetric SOR/Jacobi, the KSPSolve get
slower and performs on CPU.
However, how can I diagnose if the computations are perfomed on GPU or not?

Thanks very much,

Nicola

log_cpu
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log_gpu
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