Thanks for your interest,

I already shutdown preconditioner as shown in notebook with;

solvers.linearPCGSolver.LinearPCGSolver(precon=None, iterations=500,
tolerance=1e-15)

I think this should turn preconditioner off but still code run completed at
around 55 sec with 8 cores (serial was around 41 sec). So I think problem
is beyond preconditioner. I paste last version of the code below if you'd
like to try.

http://pastebin.com/VL4dWCJr

I also would like to know is there a decent way to profile parallel run may
be it can gave me a clue on problem.

Serbulent


2014-09-30 17:43 GMT+03:00 Daniel Wheeler <[email protected]>:

> On Mon, Sep 29, 2014 at 4:09 PM, Serbulent UNSAL <[email protected]>
> wrote:
>
>> Thanks for help.
>>
>> Using LinearPCGSolver gives some more speed but it it still slower than
>> serial version ( 41 sec vs. 55 sec ).
>>
>
> Serbulent,
>
> It seems that in this notebook,
> http://nbviewer.ipython.org/github/wd15/fipy-efficiency/blob/master/notebooks/FiPy-IPython.ipynb,
> the serial version PCG using Trilinos is faster than the serial version of
> PySparse without preconditioning. Preconditioning with Trilinos can often
> impact efficiency quite heavily.
>
>
>
>>
>> I tried to use Gmsh mesh with using workaround defined at
>> http://wd15.github.io/2014/01/30/fipy-trilinos-anaconda/
>> But Gmsh is even slower than normal mesh.
>>
>
> I don't think I factored that in when writing up the notebooks. I might
> look into that.
>
>
>>
>> Since I use a big mesh (400x400) I think, I will have communication issue
>> that defined at the end of the first notebook.
>>
>
> Take a look at the second notebook,
> http://nbviewer.ipython.org/github/wd15/fipy-efficiency/blob/master/notebooks/cluster.ipynb,
> 400x400 should be large enough to get some reasonable scaling.
>
>
>
>>
>> I'm open for any alternative strategies and suggestions.
>>
>
> I am not sure what to suggest. Certainly disable the preconditioners in
> Trilinos and see what happens. It may be that we need to use
> preconditioning in a less naive way in FiPy (not precondition at every
> sweep, there may be ways to do that with Trilinos).
>
> --
> Daniel Wheeler
>
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>
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