[petsc-users] VecView() comparison: BINARY vs HDF5

[Mohamad M. Nasr-Azadani]

Thanks Barry.
Well, I guess it all comes from the fact that I want it all.
I wanted to have everything done only once. Data that can be also read in a
visualization package.
Then I guess I have to stick with my old strategy of having everything
stored in binary and using a postprocessor to make hdft or vtk format data
files for visualization.

Cheers,
Mohamad


On Tue, Jan 31, 2012 at 2:39 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
> On Jan 31, 2012, at 4:34 PM, Mohamad M. Nasr-Azadani wrote:
>
> > Hi all,
> >
> > I was using VecView() to write the data to file (a vector of total size
> 50*20*10 (3D DMDA)).
> > I compared the times for two cases: PETSc's binary and also HDF5.
> > I get an enormous difference between the times I get for these two cases
> (this test is done using only one processor)
> >
> > HDF5: 16.2 (sec)
> > Binary: 0.33 (sec).
> >
> > I am using HDF5 VecView() as a magic black box writer to dump the field
> quantities. And I am not an expert on it but this order of magnitude seems
> a bit strange to me.
>
>    I am not surprised at all.  Just because HDF5 is a "defacto standard"
> and "supposedly" a good thing to use doesn't mean it will be faster than
> something else.
>
>   I would only use HDF5 when the resulting file needs to be HDF5 for some
> other software, like visualization. If you are just using the file with
> PETSc then use PETSc's binary.
>
>    Barry
>
>
> >
> > Any inputs are appreciated!
> > Best,
> > Mohamad
> >
> >
> >
>
>
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