| Pebibits per second (Pibit/s) | Yottabits per second (Ybit/s) |
|---|---|
| 1 Pebibit per second | 0.00000000112589990684 Ybit/s |
| 2 Pebibits per second | 0.00000000225179981369 Ybit/s |
| 3 Pebibits per second | 0.00000000337769972053 Ybit/s |
| 4 Pebibits per second | 0.00000000450359962737 Ybit/s |
| 5 Pebibits per second | 0.00000000562949953421 Ybit/s |
| 10 Pebibits per second | 0.0000000112589990684 Ybit/s |
| 20 Pebibits per second | 0.0000000225179981369 Ybit/s |
| 25 Pebibits per second | 0.0000000281474976711 Ybit/s |
| 50 Pebibits per second | 0.0000000562949953421 Ybit/s |
| 100 Pebibits per second | 0.000000112589990684 Ybit/s |
| Reference | Pebibits per second (Pibit/s) | Yottabits per second (Ybit/s) |
|---|---|---|
| A dial-up modem | 4.9738 × 10-11 Pibit/s | 5.6 × 10-20 Ybit/s |
| Typical home broadband | 0.0000000888178 Pibit/s | 1 × 10-16 Ybit/s |
| Gigabit Ethernet | 0.000000888178 Pibit/s | 1 × 10-15 Ybit/s |
| Streaming a 4K film | 0.0000000222045 Pibit/s | 2.5 × 10-17 Ybit/s |
The pebibit per second is a unit of data transfer rate equal to 1,024 tebibits per second, which is two to the fiftieth power bits per second. Its symbol is Pibit/s. It is the binary counterpart of the petabit per second, and the two differ by 12.6 per cent.
No deployed system runs at this rate, and the unit therefore describes either an aggregate or a laboratory result. Optical transmission records set on single fibres reach a petabit per second, and the binary figure for the same experiment is 12.6 per cent lower — a difference that matters when comparing results between papers that use different conventions.
Where the unit is genuinely appropriate is in describing structures built from powers of two. The total switching capacity of a very large network fabric, built from ports and buffers that are all binary, is a binary quantity divided by time, and reporting it in decimal units discards the arithmetic that produced it. The same applies to the summed memory bandwidth of a machine whose channel count is a power of two.
In octets a pebibit per second is 140,737,488,355,328, which is 128 tebioctets per second. That is the storage of a thousand large consumer drives moved every second, and it exists only as a total across many thousands of parallel paths inside a single facility.
The size of the discrepancy at this level is the argument for the whole IEC series in miniature. What began as a harmless 2.4 per cent at the kibibit is now an eighth, and it compounds by 2.4 per cent at every further step. A convention that was acceptable for small numbers becomes untenable for large ones, and the point of the binary prefixes is to make the distinction visible before that happens.
For a converter, the arithmetic is unremarkable: multiply or divide by 1,024 the appropriate number of times, and by eight to reach octets. What matters is that the tool does not silently substitute the decimal unit when it sees a value it cannot label precisely.
One pebibit per second equals 1,024 tebibits per second, 140,737,488,355,328 octets per second, or about 1.126 petabits per second.
The yottabit per second is a unit of data transfer rate equal to a thousand zettabits per second. Its symbol is Ybit/s. For thirty years it was the largest rate the metric system could name, and it describes a speed that has no application anywhere: not in engineering, not in research, and not in any forecast that anyone takes seriously.
Its distance from reality is easy to state. Global internet traffic averages roughly one exabit per second, so a yottabit per second is about a million times the combined communication of the entire human species. The largest single link ever built runs at a few hundred terabits per second, which is a ten-billionth of this figure.
The unit is nonetheless properly defined, and that completeness is the point. The metric system's rule is that every prefix combines with every unit without exception, so a reader who has never seen Ybit/s can decode it from the prefix alone. A system with gaps would need a table of which combinations are legal, and a table is exactly what a rule-based system exists to avoid.
There is a physical way to think about the number. A yottabit per second is 125 zettaoctets per second, and the total quantity of data humanity has ever stored is a few hundred zettaoctets. A link at this rate would therefore transmit the entire accumulated information of the species in a couple of seconds. No such body of data exists in one place to be sent, and nothing at the far end could receive it.
The prefix yotta was adopted in 1991 alongside zetta, at a conference that also had to consider which letters remained free. It stood at the top of the metric ladder until 2022, when ronna and quetta were added above it, partly because data quantities were beginning to approach the old ceiling. Rates have not followed quantities upward at the same pace.
For a converter, handling the unit is a matter of consistency rather than utility. A tool that converts every metric prefix correctly does not need to decide which of them anyone will use, and a figure written in yottabits per second — however unlikely — converts by the same rule as any other.
One yottabit per second equals 1,000 zettabits per second, 125 zettaoctets per second, or about 0.8272 yobibits per second.