So the metric prefixes were used for both Base 2 Binary and Base 10 Decimal values. Mike is correct that HDD manufacturers changed from a Base 2 Binary byte numbering system to a metric numbering system for the calculation of HDD sizes.However, before 1998 there were no standard definitions for the values of the metric byte numbering prefixes, e.g, kilo, mega, giga, tera, peta, exa.
