| Gigabits per second (Gbit/s) | Yobioctets per second (Yio/s) |
|---|---|
| 1 Gigabit per second | 1.03397576569 × 10-16 Yio/s |
| 2 Gigabits per second | 2.06795153138 × 10-16 Yio/s |
| 3 Gigabits per second | 3.10192729707 × 10-16 Yio/s |
| 4 Gigabits per second | 4.13590306277 × 10-16 Yio/s |
| 5 Gigabits per second | 5.16987882846 × 10-16 Yio/s |
| 10 Gigabits per second | 1.03397576569 × 10-15 Yio/s |
| 20 Gigabits per second | 2.06795153138 × 10-15 Yio/s |
| 25 Gigabits per second | 2.58493941423 × 10-15 Yio/s |
| 50 Gigabits per second | 5.16987882846 × 10-15 Yio/s |
| 100 Gigabits per second | 1.03397576569 × 10-14 Yio/s |
| Reference | Gigabits per second (Gbit/s) | Yobioctets per second (Yio/s) |
|---|---|---|
| A dial-up modem | 0.000056 Gbit/s | 5.79026 × 10-21 Yio/s |
| Typical home broadband | 0.1 Gbit/s | 1.03398 × 10-17 Yio/s |
| Gigabit Ethernet | 1 Gbit/s | 1.03398 × 10-16 Yio/s |
| Streaming a 4K film | 0.025 Gbit/s | 2.58494 × 10-18 Yio/s |
The gigabit per second is a unit of data transfer rate equal to one thousand million bits per second. Its symbol is Gbit/s, often written Gbps. It names the standard of wired local networking and, increasingly, of domestic fibre connections.
Gigabit Ethernet was standardised in 1998 for optical fibre and in 1999 for ordinary twisted-pair copper, and the copper version is what made it universal. It runs a hundred metres over the same cabling that carried the hundred-megabit standard before it, which meant buildings could be upgraded by replacing equipment rather than wiring. That single property fixed the gigabit as the default connection for a generation.
In octets a gigabit per second is 125 megaoctets per second. That is roughly the speed of a good mechanical hard drive and well below a modern solid-state drive, which is why gigabit networking is no longer the bottleneck it once was: the network can now outrun the storage at one end or the other in many common setups.
Domestic fibre services advertise a gigabit routinely, and the figure has become a marketing threshold more than a technical one. Practically no household can saturate it — a gigabit is enough for around two hundred simultaneous high-definition video streams — and the benefit in daily use is not throughput but the absence of congestion, which keeps latency low and steady.
Above the gigabit the ladder continues in the same steps. Ten-gigabit Ethernet is standard between servers and switches in data centres; twenty-five, forty, hundred and four-hundred-gigabit links join racks, buildings and cities. Each is a multiple of the same unit, and each is still counted in bits per second because that is what the optics and the copper actually carry.
Wireless has followed. The later wireless local network standards quote peak rates above a gigabit per second, though those figures assume a single device, ideal conditions and the full width of the channel. Real wireless throughput in a normal home is typically a third to a half of the advertised peak, and the gap widens with every additional device.
One gigabit per second equals 1,000,000,000 bits per second, 125 megaoctets per second, or about 0.9313 gibibits per second.
The yobioctet per second is a unit of data transfer rate equal to 1,024 zebioctets per second, or two to the eightieth power octets per second. Its symbol is Yio/s. It is the largest binary rate the International Electrotechnical Commission has named, and the last rung of the ladder that began with the bit per second.
At this final step the binary and decimal conventions differ by 20.9 per cent. That figure closes the argument the IEC prefixes were created to settle: a naming habit that was 2.4 per cent wrong at the kibibit per second has grown, through eight successive multiplications by 1.024, into a discrepancy of more than a fifth. No system of measurement can carry an ambiguity that large, and the whole binary series exists to remove it.
The rate itself has no referent. A yobioctet per second is more than eight million times the total instantaneous traffic of the internet, and it would transfer everything humanity has ever stored several thousand times over in a second. Nothing produces data at that rate, nothing consumes it, and nothing is designed with it in view.
That does not make the unit pointless. Defining the whole ladder in advance means that the rule — every prefix combines with every unit — is all anyone has to learn, and a rule is easier to carry than a table of exceptions. The same principle gave the metric system its complete prefix set, and the addition of ronna and quetta in 2022 extended the decimal side without any matching binary names being defined.
The practical value of a unit like this is that it makes a converter's behaviour uniform. A tool that handles the impossible cases by the same rule as the ordinary ones can be trusted not to have special cases hidden in it, and that is a property worth having in something whose whole purpose is to be relied upon.
For the reader, the whole series comes down to one character: Kio/s, Mio/s, Gio/s, Tio/s, Pio/s, Eio/s, Zio/s and Yio/s are binary; ko/s, Mo/s, Go/s, To/s, Po/s, Eo/s, Zo/s and Yo/s are decimal; and the difference between them widens from a rounding error to a fifth as you climb.
One yobioctet per second equals 1,024 zebioctets per second, 1,208,925,819,614,629,174,706,176 octets per second, or about 1.209 yottaoctets per second.