[petsc-users] When is it better to use MUMPS?

[w_ang_temp]

Thanks. I get it.







>在 2012-10-31 21:24:03，"Hong Zhang" <hzhang at mcs.anl.gov> 写道：
>Jim,


>>    In my view, the intent of parallel computing is sovling large system. As you said, MUMPS is mainly used in
 
>" the intent" does not automatically become the reality.
>All parallel direct solvers are intended to solve ill-conditioned problems as large as possible.
>But the algorithms (full matrix factorization) consume large memories and inter-processor 
>communications. Unless your matrix has special data structure, the direct solvers cannot be scalable
>in general.


>>small problems. So are they contradictory. Or, is the "Small problems and moderate-size 2D problems" just relative,
>>compared with the large system?
>Yes. 


>Hong
    







>>At 2012-10-30 23:47:59,"Jed Brown" <jedbrown at mcs.anl.gov> wrote:


>>Simple: it's better when it's faster. Small problems and moderate-size 2D problems often work well with direct solvers.

>>On Oct 30, 2012 8:29 AM, "w_ang_temp" <w_ang_temp at 163.com> wrote:

>>Hello,
    >>As is know, MUMPS is based on a direct method. When the system is big, the parallel direct solver is
>>not effective compared with the iterative solver. So when is it better to use MUMPS?
 >>   Thanks.
    >>                                     Jim









-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20121031/d44be423/attachment.html>