| Zettaoctets per second (Zo/s) | Tebibits per second (Tibit/s) |
|---|---|
| 1 Zettaoctet per second | 7275957614.18 Tibit/s |
| 2 Zettaoctets per second | 14551915228.4 Tibit/s |
| 3 Zettaoctets per second | 21827872842.6 Tibit/s |
| 4 Zettaoctets per second | 29103830456.7 Tibit/s |
| 5 Zettaoctets per second | 36379788070.9 Tibit/s |
| 10 Zettaoctets per second | 72759576141.8 Tibit/s |
| 20 Zettaoctets per second | 145519152284 Tibit/s |
| 25 Zettaoctets per second | 181898940355 Tibit/s |
| 50 Zettaoctets per second | 363797880709 Tibit/s |
| 100 Zettaoctets per second | 727595761418 Tibit/s |
| Reference | Zettaoctets per second (Zo/s) | Tebibits per second (Tibit/s) |
|---|---|---|
| A dial-up modem | 7 × 10-18 Zo/s | 0.0000000509317 Tibit/s |
| Typical home broadband | 1.25 × 10-14 Zo/s | 0.0000909495 Tibit/s |
| Gigabit Ethernet | 1.25 × 10-13 Zo/s | 0.000909495 Tibit/s |
| Streaming a 4K film | 3.125 × 10-15 Zo/s | 0.0000227374 Tibit/s |
The zettaoctet per second is a unit of data transfer rate equal to a thousand exaoctets per second, or eight zettabits per second. Its symbol is Zo/s. A link running at this rate would transfer everything humanity has ever stored in well under a second, which is the clearest way to state how far beyond present engineering it lies.
The comparison is worth making carefully. Estimates of the world's total stored data run to a few hundred zettaoctets, so a zettaoctet per second would move all of it in a few minutes at most, and a substantial fraction of it every second. Nothing could produce data at that rate and nothing could store it, so the unit describes a capacity with no possible source and no possible destination.
Energy is the constraint that makes this more than a matter of engineering effort. Transmitting a bit costs energy — in the optics, in the electronics that drive them, and in the cooling that removes the waste heat. Current optical systems use on the order of a picojoule per bit end to end. At a zettaoctet per second, that works out to gigawatts of continuous power for the link alone, which is the output of several large power stations.
That figure is not a hard physical limit but an engineering one, and it has fallen steadily. The energy cost per bit of optical transmission has dropped by orders of magnitude over forty years and continues to fall. The theoretical floor, set by thermodynamics, is far lower still, so the obstacle is technique rather than physics.
The unit's practical role is in the completeness of the prefix system rather than in any application. A table of transfer rates that stops before zetta would force anyone who needed it to invent a name, and competing invented names are how measurement systems fragment. Defining the whole ladder costs nothing and prevents that.
For a converter, the arithmetic is the same as for any other prefix: a zettaoctet per second is eight zettabits per second, a thousand exaoctets, and a million petaoctets. The rule does not change because the quantity is unattainable.
One zettaoctet per second equals 1,000 exaoctets per second, 8 zettabits per second, or about 0.8470 zebioctets per second.
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.