Data storage values
TS7700 documentation displays data storage values by using both decimal (base-10) prefixes and binary (base-2) units of measurement.
Decimal units such as K, MB, GB, and TB have commonly been used to express data storage values, though these values are more accurately expressed by using binary units such as KiB, MiB, GiB, and TiB. At the kilobyte level, the difference between decimal and binary units of measurement is relatively small (2.4%). This difference grows as data storage values increase, and when values reach terabyte levels the difference between decimal and binary units approaches 10%.
To reduce the possibility of confusion, the IBM® TS7700 Information Center represents
data storage by using both decimal and binary units. Data storage values are displayed by using the
following format:
#### decimal unit (binary unit)
By this example, the value
512 terabytes is displayed as: 512 TB (465.6 TiB)
Table 1 compares
the names, symbols, and values of the binary and decimal units. Table 2 shows
the increasing percentage of difference between binary and decimal
units.
Decimal | Binary | ||||
---|---|---|---|---|---|
Name | Symbol | Value (base-10) | Name | Symbol | Value (base-2) |
kilo | K | 103 | kibi | Ki | 210 |
mega | M | 106 | mebi | Mi | 220 |
giga | G | 109 | gibi | Gi | 230 |
tera | T | 1012 | tebi | Ti | 240 |
peta | P | 1015 | pebi | Pi | 250 |
exa | E | 1018 | exbi | Ei | 260 |
Decimal Value | Binary Value | Percentage Difference |
---|---|---|
100 kilobytes (KB) | 97.65 kibibytes (KiB) | 2.35% |
100 megabytes (MB) | 95.36 mebibytes (MiB) | 4.64% |
100 gigabytes (GB) | 93.13 gibibytes (GiB) | 6.87% |
100 terabytes (TB) | 90.94 tebibytes (TiB) | 9.06% |
100 petabytes (PB) | 88.81 pebibytes (PiB) | 11.19% |
100 exabytes (EB) | 86.73 exbibytes (EiB) | 13.27% |