Drive makers and network speeds use decimal units: 1 GB = 1,000,000,000 bytes. Windows and RAM sizes traditionally use binary units: 1 GiB = 1,073,741,824 bytes. That is why a 500 GB drive shows about 465 GB in Windows.
Example: 1 GB is 1,000 MB (decimal) or 1,024 MB (binary).
1,000 MB in decimal units, 1,024 MiB in binary units.
The advertised size is in decimal gigabytes, while the operating system reports binary gibibytes, about 7% smaller.
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