| Exabits per second (Ebit/s) | Yobibits per second (Yibit/s) |
|---|---|
| 1 Exabit per second | 0.000000827180612553 Yibit/s |
| 2 Exabits per second | 0.00000165436122511 Yibit/s |
| 3 Exabits per second | 0.00000248154183766 Yibit/s |
| 4 Exabits per second | 0.00000330872245021 Yibit/s |
| 5 Exabits per second | 0.00000413590306277 Yibit/s |
| 10 Exabits per second | 0.00000827180612553 Yibit/s |
| 20 Exabits per second | 0.0000165436122511 Yibit/s |
| 25 Exabits per second | 0.0000206795153138 Yibit/s |
| 50 Exabits per second | 0.0000413590306277 Yibit/s |
| 100 Exabits per second | 0.0000827180612553 Yibit/s |
| Reference | Exabits per second (Ebit/s) | Yobibits per second (Yibit/s) |
|---|---|---|
| A dial-up modem | 5.6 × 10-14 Ebit/s | 4.63221 × 10-20 Yibit/s |
| Typical home broadband | 1 × 10-10 Ebit/s | 8.27181 × 10-17 Yibit/s |
| Gigabit Ethernet | 0.000000001 Ebit/s | 8.27181 × 10-16 Yibit/s |
| Streaming a 4K film | 2.5 × 10-11 Ebit/s | 2.06795 × 10-17 Yibit/s |
The exabit per second is a unit of data transfer rate equal to a thousand petabits per second. Its symbol is Ebit/s. No link, no cable and no exchange point runs at this rate; the unit describes the internet as a whole, or a large part of it, at a single instant.
Global internet traffic can be expressed this way. Worldwide traffic of several hundred exaoctets a month works out to roughly one exabit per second on average, and peak hours run higher. That figure is the sum of every packet moving on every network on the planet, and it is the only quantity anyone routinely describes at this scale.
An exabit per second is 125 petaoctets per second. Nothing generates data at that rate in one place; the number is an aggregate of billions of separate flows, most of them tiny. A single video stream is a few megabits per second, so an exabit per second is on the order of a hundred million such streams running at once.
The composition of that traffic is dominated by video. Streaming services account for the largest share, followed by social platforms, software updates and cloud synchronisation. Ordinary web browsing and messaging, which people think of as the internet, are a small fraction of the total by volume even though they occupy most of the attention.
The unit also appears in projections of aggregate capacity. The total installed capacity of all submarine cables, if every wavelength on every fibre pair were lit and used simultaneously, is in the exabit-per-second range. Actual utilisation is far below that, because capacity is built ahead of demand and because routes must carry each other's traffic when a cable fails.
The prefix exa is a thousand to the sixth power. It was adopted in 1975, when nobody expected it to describe anything but astronomical quantities, and it now describes the working throughput of a communications system built by human beings. The interval between definition and everyday use was about forty years.
One exabit per second equals 1,000 petabits per second, 125 petaoctets per second, or about 0.8674 exbibits per second.
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.