Data Transfer Speed (with SI Prefixes)

In computing, a binary prefix is a set of letters that precede a unit of measure (such as a byte) to indicate multiplication by a power of two. In certain contexts in computing, such as computer memory sizes, units of information storage and communication traffic (Byte) have traditionally been reported in multiples of powers of two. The term binary prefix is intended to differentiate usage of certain symbolic abbreviations (for example, k or kilo) from the SI prefixes, which are always decimal.
Source: wikipedia