Dear all, The latest master now contains a new parallel output format that is based on the HDF5 dataset format. It's hoped we can make our I/O more efficient at very large core counts as a consequence. The default format is still our directory-based structure. I'd appreciate it if you can test this out on your simulations and let me know (a) the speed difference in reading/writing and (b) any bugs you encounter. - To enable HDF5, configure CMake with the NEKTAR_USE_HDF5 setting, which also requires NEKTAR_USE_MPI. Note that most clusters have HDF5 modules available that are usually detected by the CMake configuration (e.g. on ARCHER: module load cray-hdf5-parallel) - To run a simulation using the new format: IncNavierStokesSolver --io-format Hdf5 session.xml or put <I PROPERTY="IOFormat" VALUE="Hdf5" /> into your <SOLVERINFO> section. - To convert from XML based format (either serial or parallel) to HDF5: FieldConvert in.fld out.fld:fld:format=Hdf5 Note you don't need the session file for this. - Or the other way around: FieldConvert in.fld out.fld:fld:format=Xml Thanks also to Rupert Nash and Michael Bareford at EPCC for helping get this done as part of our eCSE funding. Cheers, Dave -- David Moxey (Research and Teaching Fellow) d.moxey@imperial.ac.uk | www.imperial.ac.uk/people/d.moxey Room 364, Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK.