The HDF Group is planning to write a document on guidelines for setting chunksizes, and we intend to also provide better documentation on this subject. For now, you may be interested in this section on chunking from the most recent netCDF workshop: http://www.unidata.ucar.edu/netcdf/workshops/2008/nc4chunking/ and slides 54 through 67 of this presentation by Elena Pourmal from a recent HDF workshop: http://www.hdfeos.org/workshops/ws12/presentations/day1/exp.ppt Chunk sizes and shapes are a permanent property of variables in a netCDF-4 file, so you should consider how the data will be accessed in the future to help determine what shapes to use. In particular, if the data will be read many times and written only once, it's important to use chunks that help optimize how it will be read rather than how much time it takes to write. --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: KVY-259447 Department: Support netCDF Priority: Emergency Status: Closed