| Zebibits per second (Zibit/s) | Gibibits per second (Gibit/s) |
|---|---|
| 1 Zebibit per second | 1099511627776 Gibit/s |
| 2 Zebibits per second | 2199023255552 Gibit/s |
| 3 Zebibits per second | 3298534883328 Gibit/s |
| 4 Zebibits per second | 4398046511104 Gibit/s |
| 5 Zebibits per second | 5497558138880 Gibit/s |
| 10 Zebibits per second | 10995116277760 Gibit/s |
| 20 Zebibits per second | 21990232555520 Gibit/s |
| 25 Zebibits per second | 27487790694400 Gibit/s |
| 50 Zebibits per second | 54975581388800 Gibit/s |
| 100 Zebibits per second | 109951162777600 Gibit/s |
| Reference | Zebibits per second (Zibit/s) | Gibibits per second (Gibit/s) |
|---|---|---|
| A dial-up modem | 4.74338 × 10-17 Zibit/s | 0.0000521541 Gibit/s |
| Typical home broadband | 8.47033 × 10-14 Zibit/s | 0.0931323 Gibit/s |
| Gigabit Ethernet | 8.47033 × 10-13 Zibit/s | 0.931323 Gibit/s |
| Streaming a 4K film | 2.11758 × 10-14 Zibit/s | 0.0232831 Gibit/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 gibibit per second is a unit of data transfer rate equal to 1,073,741,824 bits per second. Its symbol is Gibit/s. It is the binary counterpart of the gigabit per second, and the two now differ by 7.4 per cent, which is enough to matter in any engineering specification.
The unit belongs to the inside of a machine rather than to the network. Memory buses, processor interconnects and the links between chips on the same board all move a power-of-two number of bits per clock cycle, so their throughput is naturally expressed with a binary prefix. A bus sixty-four bits wide clocked at a given frequency delivers a rate that is a binary multiple of that frequency.
Networking, by contrast, is decimal all the way down. Gigabit Ethernet carries exactly one thousand million bits per second, not 1,073,741,824, and the symbol rate on the wire is chosen to make that so. Confusing the two overstates a link's capacity by seven per cent, which in a capacity plan is the difference between adequate and insufficient.
In octets a gibibit per second is 134,217,728, or 128 mebioctets per second. That is close to the throughput of a fast mechanical hard drive and well below a modern solid-state drive, so it sits at the point where storage and internal buses meet and where matching their rates becomes a design question.
Benchmark tools are the commonest place to see the unit written correctly. A memory bandwidth test that allocates buffers in powers of two and measures how long they take to traverse naturally reports in gibibits or gibioctets per second, and a well-written tool says so explicitly rather than rounding to the decimal unit.
The reason to insist on the distinction here rather than lower down the scale is arithmetic. At the kibibit the gap was 2.4 per cent and could be ignored; here it is nearly a thirteenth, and it grows by a further 2.4 per cent at every step above. Getting into the habit at this level costs nothing and avoids compounding errors later.
One gibibit per second equals 1,073,741,824 bits per second, 134,217,728 octets per second, or about 1.074 gigabits per second.