CSVs, in addition to being slow to parse (in practice, 40-100MB/s is the typical window, see some benchmarks here http://wesmckinney.com/blog/pandas-and-apache-

CSVs, in addition to being slow to parse (in practice, 40-100MB/s is the typical window, see some benchmarks here http://wesmckinney.com/blog/pandas-and-apache-arrow/ http://wesmckinney.com/blog/pandas-and-apache-arrow/), drop types (which have to be inferred), sometimes in a way that cannot be recovered (factor / category levels). By comparison, Feather performs very close to disk performance. So speeds exceeding 500 MB/s (versus < 100MB/s for CSV) are common.