Thanks,

for help, I have read both algorithms in Saad. My main problem in understanding 
of the procedure is how the decompose the domain. At the moment I decompose 
with jacobi block method(without overlapping) and I run on each block LIU(0) in 
parallel after that I put each solution together for an CG solver. With that my 
iteration number raises instead of break down, so there must be something wrong 
:).

Perhaps you know the order of the methods? First Jacobi-block then 
additive-Schwarz then ILU(0) and at least cg loop, or is it another order?

Kind regards
J?rgen D?rrwang

Von: petsc-users-bounces at mcs.anl.gov [mailto:petsc-users-bounces at 
mcs.anl.gov] Im Auftrag von Matthew Knepley
Gesendet: Montag, 6. Juni 2011 09:39
An: PETSc users list
Betreff: Re: [petsc-users] Some papers for additive schwarz and blocked jacobi?

2011/6/6 D?rrwang, J?rgen <Juergen.Duerrwang at 
iosb.fraunhofer.de<mailto:Juergen.Duerrwang at iosb.fraunhofer.de>>
Hi,

I am working on a NVIDIA CUDA improved cg solver, with fast preconditioning. 
Since I have tested PETSC PCJACOBI with ILU(0) on each block I have some nice 
results. Unfortunately the pc is on CPU, so I try to port them on GPU. Now my 
question is, has body some material about this PETSC implementation?

The ILU(0) algorithm is described in Yousef Saad's book on Iterative Methods. 
It is notoriously hard to parallelize.
ASM and Block-Jacobi jsut decompose the system into blocks. They are also 
described in the book.

   Matt


Kind regards,
J?rgen D?rrwang



--
What most experimenters take for granted before they begin their experiments is 
infinitely more interesting than any results to which their experiments lead.
-- Norbert Wiener
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