| Zebibits per second (Zibit/s) | Exbioctets per second (Eio/s) |
|---|---|
| 1 Zebibit per second | 128 Eio/s |
| 2 Zebibits per second | 256 Eio/s |
| 3 Zebibits per second | 384 Eio/s |
| 4 Zebibits per second | 512 Eio/s |
| 5 Zebibits per second | 640 Eio/s |
| 10 Zebibits per second | 1280 Eio/s |
| 20 Zebibits per second | 2560 Eio/s |
| 25 Zebibits per second | 3200 Eio/s |
| 50 Zebibits per second | 6400 Eio/s |
| 100 Zebibits per second | 12800 Eio/s |
| Reference | Zebibits per second (Zibit/s) | Exbioctets per second (Eio/s) |
|---|---|---|
| A dial-up modem | 4.74338 × 10-17 Zibit/s | 6.07153 × 10-15 Eio/s |
| Typical home broadband | 8.47033 × 10-14 Zibit/s | 1.0842 × 10-11 Eio/s |
| Gigabit Ethernet | 8.47033 × 10-13 Zibit/s | 1.0842 × 10-10 Eio/s |
| Streaming a 4K film | 2.11758 × 10-14 Zibit/s | 2.71051 × 10-12 Eio/s |
The zebibit per second is a unit of data transfer rate equal to two to the seventieth power bits per second, which is 1,024 exbibits per second. Its symbol is Zibit/s. It is the binary counterpart of the zettabit per second, and the two differ by 18.1 per cent — approaching a fifth.
Nothing runs at this rate, and nothing is designed to. A zebibit per second is about a thousand times the total instantaneous traffic of the internet, and it would move the world's entire stock of stored data in a matter of minutes. The unit exists because the IEC series, like the metric series it parallels, was defined completely rather than only as far as anyone then needed.
That completeness is a deliberate design principle rather than an oversight. A measurement system whose names run out at some arbitrary point forces every future user to improvise an extension, and improvised extensions conflict with one another. Defining the whole ladder in advance costs nothing and removes the possibility.
The eighteen per cent gap at this level is the clearest illustration of why the binary series was needed at all. At the kibibit the two conventions differed by 2.4 per cent, which nobody noticed; the discrepancy multiplies by 1.024 at each step, and by here it is large enough that no reader could treat the two labels as interchangeable even in casual writing.
In octets a zebibit per second is 147,573,952,589,676,412,928, or 128 exbioctets per second. Expressing the same rate in every unit on the scale is an exercise rather than an application, but it is one a converter has to perform correctly, because the arithmetic does not become approximate when the quantity becomes unreachable.
The practical lesson is the one the whole binary series teaches: the lowercase i is not optional. It is the only mark in a written figure that distinguishes a power of two from a power of ten, and by this point in the scale the two are nearly a fifth apart.
One zebibit per second equals 1,024 exbibits per second, 147,573,952,589,676,412,928 octets per second, or about 1.181 zettabits per second.
The exbioctet per second is a unit of data transfer rate equal to 1,024 pebioctets per second, or two to the sixtieth power octets per second. Its symbol is Eio/s. It is the binary counterpart of the exaoctet per second, and the two differ by 15.3 per cent.
No machine, network or aggregate reaches this rate. An exbioctet per second is more than eight times the total instantaneous traffic of the entire internet, and it would move the world's whole stock of stored data in a matter of minutes. The unit describes a capacity with no source that could supply it and no destination that could take it in.
Two to the sixtieth is nevertheless a familiar number in computing, because it is the size of the address space a 64-bit machine can reach in octets divided by sixteen. The same power of two turns up in filesystem limits, in memory maps and in the design of every system built on that architecture, so the quantity is well known even though no rate approaches it.
The unit exists because the IEC series was defined completely. Every binary prefix pairs with every unit, exactly as every metric prefix does, so that a reader who has never seen Eio/s can decode it from the prefix alone. A system with gaps would need a table of permitted combinations, which is precisely what a rule-based system exists to avoid.
The difference from the decimal unit is worth restating at each level because it compounds. At the kibioctet it was 2.4 per cent, here it is more than an eighth, and at the yobioctet it will be more than a fifth. That growth is the reason the binary prefixes were created, and it is why the lowercase i has to be written even in figures nobody will check.
For a converter, the treatment is mechanical: six multiplications by 1,024 from octets, or the equivalent divisions coming down. The value of doing it correctly is not that anyone will use the result, but that a tool which handles every case the same way can be trusted on the cases that matter.
One exbioctet per second equals 1,024 pebioctets per second, 1,152,921,504,606,846,976 octets per second, or about 1.153 exaoctets per second.