| Tebibits per second (Tibit/s) | Exbioctets per second (Eio/s) |
|---|---|
| 1 Tebibit per second | 0.000000119209289551 Eio/s |
| 2 Tebibits per second | 0.000000238418579102 Eio/s |
| 3 Tebibits per second | 0.000000357627868652 Eio/s |
| 4 Tebibits per second | 0.000000476837158203 Eio/s |
| 5 Tebibits per second | 0.000000596046447754 Eio/s |
| 10 Tebibits per second | 0.00000119209289551 Eio/s |
| 20 Tebibits per second | 0.00000238418579102 Eio/s |
| 25 Tebibits per second | 0.00000298023223877 Eio/s |
| 50 Tebibits per second | 0.00000596046447754 Eio/s |
| 100 Tebibits per second | 0.0000119209289551 Eio/s |
| Reference | Tebibits per second (Tibit/s) | Exbioctets per second (Eio/s) |
|---|---|---|
| A dial-up modem | 0.0000000509317 Tibit/s | 6.07153 × 10-15 Eio/s |
| Typical home broadband | 0.0000909495 Tibit/s | 1.0842 × 10-11 Eio/s |
| Gigabit Ethernet | 0.000909495 Tibit/s | 1.0842 × 10-10 Eio/s |
| Streaming a 4K film | 0.0000227374 Tibit/s | 2.71051 × 10-12 Eio/s |
The tebibit per second is a unit of data transfer rate equal to 1,099,511,627,776 bits per second, which is 1,024 gibibits per second. Its symbol is Tibit/s. It is the binary counterpart of the terabit per second, and the two differ by 10 per cent.
Ten per cent is the point at which the distinction becomes a matter of money rather than of pedantry. A supplier quoting a system at a hundred terabits per second and a customer measuring a hundred tebibits per second are not describing the same performance, and the difference is ten terabits — more than most organisations' entire external connectivity.
The rate belongs to the interior of very large machines. The aggregate memory bandwidth of a rack of accelerators, or the internal switching capacity of a large network chip, reaches this range, and both are built from power-of-two structures: memory channels of fixed binary width, switch ports in powers of two, buffers sized in binary. Expressing their totals with binary prefixes preserves the arithmetic that produced them.
In octets a tebibit per second is 137,438,953,472, or 128 gibioctets per second. That is more than any single storage device can supply and more than any external cable carries. It is a figure that describes something happening inside a cabinet, between chips connected by short traces on a board, where the physical distance is measured in centimetres.
Optical research also brushes this range. A laboratory demonstration carrying a petabit per second down one fibre is a thousand times higher, but individual wavelength channels and the electronics driving them work at tebibit-scale aggregates, and papers reporting them often state the binary figure because the underlying frame sizes are binary.
The habit of writing the lowercase i is worth keeping even where the reader is unlikely to check. A number written unambiguously can be converted correctly by anyone who reads it later; one written ambiguously cannot be repaired, and at ten per cent the ambiguity is no longer harmless.
One tebibit per second equals 1,024 gibibits per second, 137,438,953,472 octets per second, or about 1.100 terabits per second.
The exbioctet per second is a unit of data transfer rate equal to 1,024 pebioctets per second, or two to the sixtieth power octets per second. Its symbol is Eio/s. It is the binary counterpart of the exaoctet per second, and the two differ by 15.3 per cent.
No machine, network or aggregate reaches this rate. An exbioctet per second is more than eight times the total instantaneous traffic of the entire internet, and it would move the world's whole stock of stored data in a matter of minutes. The unit describes a capacity with no source that could supply it and no destination that could take it in.
Two to the sixtieth is nevertheless a familiar number in computing, because it is the size of the address space a 64-bit machine can reach in octets divided by sixteen. The same power of two turns up in filesystem limits, in memory maps and in the design of every system built on that architecture, so the quantity is well known even though no rate approaches it.
The unit exists because the IEC series was defined completely. Every binary prefix pairs with every unit, exactly as every metric prefix does, so that a reader who has never seen Eio/s can decode it from the prefix alone. A system with gaps would need a table of permitted combinations, which is precisely what a rule-based system exists to avoid.
The difference from the decimal unit is worth restating at each level because it compounds. At the kibioctet it was 2.4 per cent, here it is more than an eighth, and at the yobioctet it will be more than a fifth. That growth is the reason the binary prefixes were created, and it is why the lowercase i has to be written even in figures nobody will check.
For a converter, the treatment is mechanical: six multiplications by 1,024 from octets, or the equivalent divisions coming down. The value of doing it correctly is not that anyone will use the result, but that a tool which handles every case the same way can be trusted on the cases that matter.
One exbioctet per second equals 1,024 pebioctets per second, 1,152,921,504,606,846,976 octets per second, or about 1.153 exaoctets per second.