| Zettabits per second (Zbit/s) | Mebioctets per second (Mio/s) |
|---|---|
| 1 Zettabit per second | 119209289550781 Mio/s |
| 2 Zettabits per second | 238418579101562 Mio/s |
| 3 Zettabits per second | 357627868652344 Mio/s |
| 4 Zettabits per second | 476837158203125 Mio/s |
| 5 Zettabits per second | 596046447753906 Mio/s |
| 10 Zettabits per second | 1.19209289551 × 1015 Mio/s |
| 20 Zettabits per second | 2.38418579102 × 1015 Mio/s |
| 25 Zettabits per second | 2.98023223877 × 1015 Mio/s |
| 50 Zettabits per second | 5.96046447754 × 1015 Mio/s |
| 100 Zettabits per second | 1.19209289551 × 1016 Mio/s |
| Reference | Zettabits per second (Zbit/s) | Mebioctets per second (Mio/s) |
|---|---|---|
| A dial-up modem | 5.6 × 10-17 Zbit/s | 0.00667572 Mio/s |
| Typical home broadband | 1 × 10-13 Zbit/s | 11.9209 Mio/s |
| Gigabit Ethernet | 1 × 10-12 Zbit/s | 119.209 Mio/s |
| Streaming a 4K film | 2.5 × 10-14 Zbit/s | 2.98023 Mio/s |
The zettabit per second is a unit of data transfer rate equal to a thousand exabits per second. Its symbol is Zbit/s. No system on Earth moves data at this rate, and none is planned; the unit exists because the metric system defines every prefix for every unit, whether or not the combination has yet been needed.
To see how far off it is, take the whole internet. Global traffic at present runs at roughly one exabit per second on average, so the entire planet's communications would have to grow a thousandfold to reach one zettabit per second. At the growth rates of the last two decades that would take somewhere between twenty and thirty years, which is precisely the sort of extrapolation that has been wrong in both directions before.
A zettabit per second is 125 exaoctets per second. Since global data storage manufacturing runs at a few hundred exaoctets a year, a link at this rate would transfer the world's entire annual production of new storage capacity in a couple of seconds. Nothing could be stored at the far end; the data would have to be processed and discarded as it arrived.
That last point is not as fanciful as it sounds. Several existing systems already discard almost everything they receive: particle detectors, radio telescope arrays and network monitoring systems all process far more than they keep, because keeping it is impossible and unnecessary. A zettabit-per-second link would be an extreme case of an architecture that already exists.
The physical obstacles are less absolute than they might appear. The theoretical capacity of a single optical fibre is far above what is used today, and the practical limits come from amplifier noise, non-linear effects and the electronics at each end rather than from the glass itself. Aggregating enough fibres would reach a zettabit per second; the difficulty is that nobody has a reason to.
For a converter, the unit matters because forecasts and capacity models are written in whatever unit keeps the numbers legible. A projection that reaches into the 2050s may reasonably state totals in zettabits per second, and a reader needs to be able to convert that into something familiar.
One zettabit per second equals 1,000 exabits per second, 125 exaoctets per second, or about 0.8470 zebibits per second.
The mebioctet per second is a unit of data transfer rate equal to 1,048,576 octets per second, which is 1,024 kibioctets per second. Its symbol is Mio/s. It is the unit that disc benchmarks, copy tools and backup programs report in, and one of the few binary units most people see regularly without noticing.
Storage measurement produces it naturally. A benchmark writes and reads blocks whose size is a power of two, times the operation, and divides. The result is a binary rate, and reporting it as such preserves the arithmetic. A tool that converted to decimal megaoctets would introduce a 4.9 per cent adjustment for no purpose other than to match a marketing convention.
That five per cent is exactly where the two conventions diverge visibly for consumers. A drive advertised at 550 megaoctets per second and measured at 524 mebioctets per second is performing precisely as claimed; the numbers differ only because one is decimal and the other binary. A great deal of complaint about storage performance is this arithmetic misread as a shortfall.
For everyday sizes, one mebioctet per second copies a photograph in three seconds and a two-gigaoctet film in about half an hour. Modern drives run hundreds or thousands of times faster, so the unit is now the resolution at which small differences are reported rather than the scale of the whole figure.
The unit also appears in memory and cache measurements, in database throughput reports and in the output of the low-level commands that write disc images. All of these count in binary blocks because the underlying structures are binary, and all of them report in mebioctets per second because that is what the count divided by the time actually gives.
The habit of writing the lowercase i is worth keeping. It costs one character and it tells a later reader which of two conventions produced the number, which is information that cannot be recovered from context once it has been left out.
One mebioctet per second equals 1,048,576 octets per second, 1,024 kibioctets per second, or about 1.049 megaoctets per second.