[petsc-users] dmmg_grid_sequence

[Xuefeng Li]

Hi, all.

I am using multigrid with DMMG (5 levels) in my petsc program.
Turning on the dmmg_grid_sequence option seems
to slow down the program dramatically. For instance,
the program converges in 3 iterations in 6.270e+01 sec
when dmmg_grid_sequence is OFF; it also converges
in 3 iterations but in 1.699e+04 sec when dmmg_grid_sequence
is ON.

Is this typical of petsc (I'm using petsc-3.1-p8)?
Are there ways to improve the performance when
dmmg_grid_sequence is ON?

Regards,

--Xuefeng Li, (504)865-3340(phone)
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