• Chunking: can be tailored to make most common access patterns more efficient
• Compression: can speed up access significantly
• Efficient schema changes: allow adding metadata without moving data
• Endianness: can be specified to avoid byte-swapping during I/O
• Scalability: can support larger file sizes, more data objects, parallel I/O
• Use of netCDF-4 classic model format can exploit all the performance features above without requiring changes to programs that read the data.

Other netCDF-4 performance features not in netCDF-4 classic model:

• Compound data types: may speed up accessing structured data, because it's stored together

2011 Unidata NetCDF Workshop > Formats and Performance