Best way to write zone ordered data in a collective way (Fortran)

#1

Hi everyone,
I hope that I can ask for some hint here since I am new in this topic. I would like to implement the most effective way (collective) to write down a set of ordered data in a MPI Fortran CFD code by means of parallel HDF5. In each MPI process, I have NZ zones, and in each of them there are there are some 3d variables in a structure
VAR(Z)%R(NI(Z),NJ(Z),NK(Z))
where R is a variable (with some other with the same dimension) and NI(Z), NJ(Z),NK(Z) are the number of cells in dimensions 1,2,3.
Thank you in advance.

#2

Have you looked into using CGNS, cgns.org?
It works with Fortran and is tuned to use HDF5 as the backend when doing parallel IO.

#3

I have considered cgns, but I would like to focus on performances. Since cgns relays over hdf5, I think that there is a little bit of overhead, or am I wrong? Thank you.