| Zebioctets per second (Zio/s) | Octets per second (octet/s) |
|---|---|
| 1 Zebioctet per second | 1.18059162072 × 1021 octet/s |
| 2 Zebioctets per second | 2.36118324143 × 1021 octet/s |
| 3 Zebioctets per second | 3.54177486215 × 1021 octet/s |
| 4 Zebioctets per second | 4.72236648287 × 1021 octet/s |
| 5 Zebioctets per second | 5.90295810359 × 1021 octet/s |
| 10 Zebioctets per second | 1.18059162072 × 1022 octet/s |
| 20 Zebioctets per second | 2.36118324143 × 1022 octet/s |
| 25 Zebioctets per second | 2.95147905179 × 1022 octet/s |
| 50 Zebioctets per second | 5.90295810359 × 1022 octet/s |
| 100 Zebioctets per second | 1.18059162072 × 1023 octet/s |
| Reference | Zebioctets per second (Zio/s) | Octets per second (octet/s) |
|---|---|---|
| A dial-up modem | 5.92923 × 10-18 Zio/s | 7000 octet/s |
| Typical home broadband | 1.05879 × 10-14 Zio/s | 12500000 octet/s |
| Gigabit Ethernet | 1.05879 × 10-13 Zio/s | 125000000 octet/s |
| Streaming a 4K film | 2.64698 × 10-15 Zio/s | 3125000 octet/s |
The zebioctet per second is a unit of data transfer rate equal to 1,024 exbioctets per second, or two to the seventieth power octets per second. Its symbol is Zio/s. It is the binary counterpart of the zettaoctet per second, and the two differ by 18.1 per cent.
A link running at this rate would transfer everything humanity has ever stored several times over in a single second. That is the plainest way to describe how far it lies beyond anything that exists, is planned, or has been seriously proposed. The unit is a name for a quantity, not a description of a thing.
It is worth being precise about why such names are still defined. A measurement system is a set of rules, and the value of a rule is that it applies without exception. The moment a system says that certain prefix-and-unit combinations are legal and others are not, every user must carry a table instead of a rule, and different users will carry different tables. Complete definition is cheaper and safer.
The physical obstacles are not merely large but qualitative. At a zebioctet per second, the energy needed to switch the required number of states, even at the thermodynamic minimum, becomes a substantial power; the practical figure for real electronics is many orders of magnitude above that; and the number of parallel channels required exceeds anything that could be built and cooled. These are not engineering targets.
The 18.1 per cent gap from the decimal unit continues the pattern that runs through the whole binary series. Each step multiplies the discrepancy by 1.024, so a convention that was harmless at the kibioctet has become, by this point, a difference no reader could overlook. Making that visible is the purpose the IEC prefixes serve.
In practice, a converter meets this unit only in a complete table or in a document exploring theoretical limits. Handling it correctly costs nothing and demonstrates that the tool applies its rules uniformly, which is the property that makes its ordinary answers trustworthy.
One zebioctet per second equals 1,024 exbioctets per second, 1,180,591,620,717,411,303,424 octets per second, or about 1.181 zettaoctets per second.
The octet per second is a unit of data transfer rate equal to eight bits per second. Its symbol is octet/s. It is the unit in which software reports transfer speeds, as against the bits per second in which hardware and network services advertise them, and the factor of eight between the two conventions is the source of endless confusion.
The division of labour is consistent once it is understood. Anything describing a physical link — an Ethernet port, a fibre connection, a radio channel, a broadband package — is quoted in bits per second, because bits are what the signalling actually carries. Anything describing a file moving from one place to another is quoted in octets per second, because files are measured in octets.
A download manager that reports 12 megaoctets per second on a connection sold as 100 megabits per second is not disagreeing with the advertisement; it is stating the same rate in the other convention, and the arithmetic between them is a division by eight. Recognising this immediately removes the most common cause of complaint about internet speed.
Individual octets per second appear in the same narrow places as individual bits: deep-space telemetry, low-power sensor links, and the slowest legacy serial connections. A rate of a hundred octets per second would move a page of text in about twenty seconds, which was a normal experience in the 1970s and is unimaginable now.
The unit also underlies the way disc and interface throughput is described. A drive that sustains 500 megaoctets per second is moving four gigabits per second across its interface, and matching the two figures is a routine part of system design: an interface rated in gigabits must be compared with a drive rated in octets, and the factor of eight decides whether one starves the other.
Storage tools reinforce the convention. Every file copy utility, backup program and command-line transfer tool reports in octets per second or its multiples, and every network measurement tool reports in bits per second. A person reading both at once has to keep the conversion in mind, which is exactly what makes the distinction worth stating explicitly.
One octet per second equals 8 bits per second, 0.008 kilobits per second, or 0.001 kilooctets per second.