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


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
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.


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


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.