| Yobibits (Yibit) | Gibioctets (Gio) |
|---|---|
| 1 Yobibit | 140737488355328 Gio |
| 2 Yobibits | 281474976710656 Gio |
| 3 Yobibits | 422212465065984 Gio |
| 4 Yobibits | 562949953421312 Gio |
| 5 Yobibits | 703687441776640 Gio |
| 10 Yobibits | 1.40737488355 × 1015 Gio |
| 20 Yobibits | 2.81474976711 × 1015 Gio |
| 25 Yobibits | 3.51843720888 × 1015 Gio |
| 50 Yobibits | 7.03687441777 × 1015 Gio |
| 100 Yobibits | 1.40737488355 × 1016 Gio |
| Reference | Yobibits (Yibit) | Gibioctets (Gio) |
|---|---|---|
| A plain text message (160 characters) | 1.05879 × 10-21 Yibit | 0.000000149012 Gio |
| A three-minute MP3 | 1.98523 × 10-17 Yibit | 0.00279397 Gio |
| A smartphone photo | 2.64698 × 10-17 Yibit | 0.00372529 Gio |
| A high-definition film | 2.64698 × 10-14 Yibit | 3.72529 Gio |
| A dual-layer Blu-ray disc | 3.30872 × 10-13 Yibit | 46.5661 Gio |
The yobibit is a unit of digital information equal to two to the eightieth power bits, which is 1,024 zebibits. Its symbol is Yibit. It is the largest of the binary prefixes defined by the International Electrotechnical Commission, and the binary counterpart of the yottabit.
At this step the two conventions differ by 20.9 per cent. That gap is the culmination of the argument for the binary prefixes: a naming habit that was 2.4 per cent wrong at the kibibit is now a fifth wrong, which no engineering document can tolerate. The IEC series stops here because the decimal series stopped at yotta when it was defined in 1998.
When the metric system gained ronna and quetta in 2022, the binary series was not extended to match. There are no accepted names above yobi, so a quantity of two to the ninetieth bits has no short form and must be written out. This is a gap in the system that will presumably be filled when someone needs it, though at present nothing comes close.
A yobibit is 151,115,727,451,828,646,838,272 octets, or 128 zebioctets. The world's entire stock of data is somewhere in the low hundreds of zettaoctets, which is a fraction of a per cent of a yobioctet. Nothing at this scale has been built, is being built, or is presently planned.
The unit is nevertheless properly defined, and that completeness has a purpose. A measurement system whose rules run out at a certain size forces every future user to invent an extension, and competing extensions are how ambiguity begins. Defining the whole ladder in advance costs nothing and prevents that.
For anyone reading technical documents, the practical lesson of the whole binary series is the lowercase i. Kibit, Mibit, Gibit, Tibit, Pibit, Eibit, Zibit and Yibit are binary; kbit, Mbit, Gbit, Tbit, Pbit, Ebit, Zbit and Ybit are decimal; and the difference between them grows from negligible to a fifth as you climb. A writer who omits the i has left the reader to guess.
One yobibit equals 1,024 zebibits, 151,115,727,451,828,646,838,272 octets, or about 1.209 yottabits.
The gibioctet is a unit of digital information equal to 1,073,741,824 octets, which is 1,024 mebioctets. Its symbol is Gio. It is the binary counterpart of the gigaoctet, and the 7.4 per cent difference between them is the single most common cause of confusion about data units.
This is the unit in which computer memory is actually sold, whatever the packaging says. A module labelled 8 GB holds 8 gibioctets, which is 8.59 gigaoctets. It could not hold anything else: memory addressing is binary, and a module with a decimal capacity would leave part of its address range unpopulated. The label is a convenient shorthand rather than a measurement.
Storage, by contrast, is genuinely decimal. A drive sold as 500 gigaoctets holds five hundred thousand million octets, and the operating system divides that by 1,024 three times and reports 465.7 gibioctets. The two figures describe the same hardware. Neither party is being dishonest; they are simply counting in different bases, and the labelling convention differs by industry.
Cloud computing has made the distinction visible in contracts. Virtual machine sizes, container memory limits and the parameters that control how much memory a program may use are all specified in gibioctets, because they map onto real memory pages. A limit of 4 GB set in a decimal-minded tool and 4 GiB set in a binary one differ by nearly three hundred megaoctets, which is enough to change whether a program runs.
For everyday scale, a gibioctet holds about a thousand books as plain text, a few hundred photographs, or twenty minutes of high-definition video. It is roughly what a modern web browser occupies in memory with a dozen pages open, which is a fair illustration of how the standard for what counts as a small amount has moved.
The correct symbol is Gio, and it appears in system tools, in virtualisation documentation and in standards. Where a document writes GB for memory, the safe reading is gibioctets; where it writes GB for a disc or a network, the safe reading is gigaoctets. The habit of checking which is meant costs a second and prevents a seven per cent error.
One gibioctet equals 1,073,741,824 octets, 1,024 mebioctets, 8 gibibits, or about 1.074 gigaoctets.