• "A basic test for data file self-consistency, the absence of a checksum capability, prevents netCDF from being an acceptable archival format."
• "... it can be quite time consuming to read time series that are stored in a record variable in a large dataset."

NetCDF-4 note:  provides option of checksums for each chunk. If you only access a small amount of data in a large file, only a few checksums need to be checked.

2010 Unidata NetCDF Workshop > Formats and Performance