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So this sort of memory consumption is expected? Is it possible to
reduce is somehow? I'm not sure about underlying petsc object but it
looks like these additional objects require more memory than the actual
vector itself.<br>
<br>
Cheers,<br>
Denis<br>
<br>
Matthew Knepley wrote:
<blockquote
cite="mid:a9f269830911221841g43c0e54ap4d69593080d5a52d@mail.gmail.com"
type="cite">It is not simple, but it is scalable, meaning in the limit
of large N, the memory will be constant on<br>
each processor. When it is created, the VecScatter objects mapping
global to local vecs are created.<br>
<br>
Matt<br>
<br>
<div class="gmail_quote">On Sun, Nov 22, 2009 at 8:29 PM, Denis
Teplyashin <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:denist@al.com.au">denist@al.com.au</a>></span> wrote:<br>
<blockquote class="gmail_quote"
style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi
guys,<br>
<br>
I'm a bit confused with distributed array memory consumption. I did a
simple test like this one:<br>
ierr = DACreate3d(PETSC_COMM_WORLD, DA_NONPERIODIC, DA_STENCIL_BOX,
1000, 1000, 1000, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, 1, 1,
PETSC_NULL, PETSC_NULL, PETSC_NULL , &da);<br>
and then checked memory with PetscMemoryGetCurrentUsage and
PetscMemoryGetMaximumUsage. Running this test using mpi on one core
gives me this result: current usage 3818Mb and maximum usage 7633Mb.
And this is the result after creating just a DA without actual vectors.
Running the same test on two cores gives me even more interesting
result: rank 0 - 9552/11463Mb and rank 1 - 5735/5732Mb.<br>
Is it what i should expect in general or am i doing something wrong? Is
there a simple formula which could show how much memory i would need to
allocate and array with given resolution?<br>
<br>
Thanks in advance,<br>
<font color="#888888">Denis<br>
</font></blockquote>
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<br>
<br clear="all">
<br>
-- <br>
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.<br>
-- Norbert Wiener<br>
</blockquote>
<br>
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