pnetcdf 0.9.0 versus hdf5 1.4.5

[John Tannahill]

Rob,

I am wrapping up my parallel netCDF work.  Timing results look very good
with respect to serial netCDF (with my test codes).

I had some parallel I/O folks here translate my parallel netCDF test code
to parallel HDF5.  It proved pretty difficult to do and equally as hard
to get the code compiled and linked on at least one machine of interest.

Well, at long last, I have the parallel netcdf and the parallel hdf5 test
codes running on NERSC's IBM SP (seaborg).  I was hoping that parallel
netCDF would perform well against HDF5, but actually the reverse appears
to be the case.  The HDF5 reads are ~2.2 times faster that pnetcdf and the
HDF5 writes are ~3.7 times faster!?

I was hoping to finish my writeup by the end of the week, but could push
things off a bit if you folks want to take a look at this set of test
codes and see what you think.  I would be happy to share them with pnetcdf
developers, but I would not want to make them part of the pnetcdf
distribution at this point.

Regards,
John

-- 
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John R. Tannahill
Lawrence Livermore Nat. Lab.
P.O. Box 808, M/S L-103
Livermore, CA  94551
925-423-3514
Fax:  925-423-4908
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