| Yobibits per second (Yibit/s) | Exbibits per second (Eibit/s) |
|---|---|
| 1 Yobibit per second | 1048576 Eibit/s |
| 2 Yobibits per second | 2097152 Eibit/s |
| 3 Yobibits per second | 3145728 Eibit/s |
| 4 Yobibits per second | 4194304 Eibit/s |
| 5 Yobibits per second | 5242880 Eibit/s |
| 10 Yobibits per second | 10485760 Eibit/s |
| 20 Yobibits per second | 20971520 Eibit/s |
| 25 Yobibits per second | 26214400 Eibit/s |
| 50 Yobibits per second | 52428800 Eibit/s |
| 100 Yobibits per second | 104857600 Eibit/s |
| Reference | Yobibits per second (Yibit/s) | Exbibits per second (Eibit/s) |
|---|---|---|
| A dial-up modem | 4.63221 × 10-20 Yibit/s | 4.85723 × 10-14 Eibit/s |
| Typical home broadband | 8.27181 × 10-17 Yibit/s | 8.67362 × 10-11 Eibit/s |
| Gigabit Ethernet | 8.27181 × 10-16 Yibit/s | 8.67362 × 10-10 Eibit/s |
| Streaming a 4K film | 2.06795 × 10-17 Yibit/s | 2.1684 × 10-11 Eibit/s |
The yobibit per second is a unit of data transfer rate equal to two to the eightieth power bits per second, which is 1,024 zebibits per second. Its symbol is Yibit/s. It is the largest binary transfer rate the International Electrotechnical Commission has named, and the binary counterpart of the yottabit per second.
At this final step the binary and decimal conventions differ by 20.9 per cent, and that number is the conclusion of the argument the IEC prefixes were created to settle. A naming habit that was 2.4 per cent wrong at the kibibit has grown, through eight successive multiplications by 1.024, into a discrepancy of more than a fifth. No measurement system can carry an ambiguity that large.
The unit describes nothing. Global internet traffic runs at roughly an exabit per second, so a yobibit per second is over a million times the total communication of the human species. No link, no aggregate and no forecast reaches it, and none is expected to.
The binary series stops here because the decimal series stopped at yotta when the IEC standard was written in 1998. When ronna and quetta were added to the metric system in 2022, no matching binary names were defined, so a rate of two to the ninetieth bits per second has no accepted short form. That gap will presumably be filled if it is ever needed, which at present it is not.
Defining a rung of a ladder nobody has climbed still has a purpose. A system whose names run out forces its users to improvise, and improvised extensions conflict; writing the whole series out in advance means the rule, rather than a table of exceptions, is all anyone has to learn. That is the same reasoning that gave the metric system its complete prefix set.
For any reader of technical material the lesson of the whole binary series is a single character. Kibit/s, Mibit/s, Gibit/s, Tibit/s, Pibit/s, Eibit/s, Zibit/s and Yibit/s are binary; kbit/s, Mbit/s, Gbit/s, Tbit/s, Pbit/s, Ebit/s, Zbit/s and Ybit/s are decimal; and the difference between them widens from a rounding error to a fifth as you climb.
One yobibit per second equals 1,024 zebibits per second, 151,115,727,451,828,646,838,272 octets per second, or about 1.209 yottabits per second.
The exbibit per second is a unit of data transfer rate equal to two to the sixtieth power bits per second, which is 1,024 pebibits per second. Its symbol is Eibit/s. It is the binary counterpart of the exabit per second, and the two differ by 15.3 per cent.
That fifteen per cent is more than the margin most engineering work allows anywhere. A quantity stated in the wrong convention at this level is not slightly imprecise but plainly wrong, and no amount of context recovers the intended figure once it has been written ambiguously. This is the situation the IEC prefixes were introduced to prevent.
No physical link approaches this rate. The unit describes aggregates: the total instantaneous traffic of the whole internet is roughly an exabit per second, so a binary exbibit per second is fifteen per cent more than everything moving on every network on the planet at a given moment.
Where a binary figure of this size arises naturally is in address arithmetic rather than in transmission. Two to the sixtieth is a number that appears throughout the design of 64-bit systems, and any rate derived from filling or traversing such an address space in a fixed time is naturally binary. Those calculations are theoretical, but they are the reason the unit is defined rather than left unnamed.
In octets an exbibit per second is 144,115,188,075,855,872, or 128 pebioctets per second. That is more storage moved per second than the world manufactures in several years, which is a way of saying that no source and no destination for such a flow could exist.
For a converter the treatment is mechanical and must be exact. Eibit/s and Ebit/s differ by an eighth, and a tool that treats them as interchangeable has introduced an error larger than the difference between many neighbouring units. The lowercase i is not decoration.
One exbibit per second equals 1,024 pebibits per second, 144,115,188,075,855,872 octets per second, or about 1.153 exabits per second.