Consumer confusion
Since the early 2000s most consumer
hard drive capacities are grouped in certain size classes measured in gigabytes. The exact capacity of a given drive is usually some number above or below the class designation. Although most manufacturers of hard disk drives and flash-memory disk devices define 1 gigabyte as 1000000000bytes, the computer operating systems used by most users (with the notable exception of
Mac OS X 10.6) usually calculate size in gibibytes by dividing the total capacity in bytes (whether it is disk capacity, file size, or system RAM) by 1073741824, but report the result with the symbol GB. This practice can be a cause of confusion, as a hard disk with a manufacturer-rated capacity of 400 gigabytes may be reported by the operating system as only 372 GB.
The
JEDEC memory standards uses the IEEE 100 nomenclatures which defines a gigabyte as 1073741824bytes (or 230 bytes).
[1]
