| Zettaoctets (Zo) | Tebioctets (Tio) |
|---|---|
| 1 Zettaoctet | 909494701.773 Tio |
| 2 Zettaoctets | 1818989403.55 Tio |
| 3 Zettaoctets | 2728484105.32 Tio |
| 4 Zettaoctets | 3637978807.09 Tio |
| 5 Zettaoctets | 4547473508.86 Tio |
| 10 Zettaoctets | 9094947017.73 Tio |
| 20 Zettaoctets | 18189894035.5 Tio |
| 25 Zettaoctets | 22737367544.3 Tio |
| 50 Zettaoctets | 45474735088.6 Tio |
| 100 Zettaoctets | 90949470177.3 Tio |
| Reference | Zettaoctets (Zo) | Tebioctets (Tio) |
|---|---|---|
| A plain text message (160 characters) | 1.6 × 10-19 Zo | 1.45519 × 10-10 Tio |
| A three-minute MP3 | 3 × 10-15 Zo | 0.00000272848 Tio |
| A smartphone photo | 4 × 10-15 Zo | 0.00000363798 Tio |
| A high-definition film | 4 × 10-12 Zo | 0.00363798 Tio |
| A dual-layer Blu-ray disc | 5 × 10-11 Zo | 0.0454747 Tio |
The zettaoctet is a unit of digital information equal to a thousand exaoctets, or a sextillion octets. Its symbol is Zo. It is the unit in which the total quantity of data in the world is now described, and the only data unit that has given its name to an era.
That name came from the phrase the zettabyte era, used from around 2016, when annual global internet traffic first exceeded one zettaoctet. Estimates of the global datasphere — every file stored anywhere, plus everything created and immediately discarded — passed a hundred zettaoctets a few years later and continue to rise by tens of zettaoctets a year.
Understanding what these figures include matters more than the numbers themselves. They count copies. A single photograph on a phone is also on the phone's backup, on two servers in a cloud provider's data centre, in a caching layer, and possibly in a machine learning training set. Counting stored octets rather than distinct works inflates the total by a large factor that nobody has ever measured precisely.
The composition of the total is dominated by things nobody looks at. Surveillance and security video, most of it overwritten within weeks, is the single largest category. Sensor and telemetry data from industrial equipment, vehicles and buildings is second. Human-authored material of any kind is a minority, and text is a rounding error within that minority.
Manufacturing sets a hard limit on the total. All the world's storage factories together produce a few hundred exaoctets of new capacity per year, which is a fraction of a zettaoctet, so most data created is never stored at all. It is processed as it arrives and thrown away, and this is a deliberate design choice rather than a failure.
For a sense of the scale, a zettaoctet would be about eight thousand million large consumer hard drives, or roughly one for every person on Earth. Stacked flat, that many drives would form a column reaching well beyond the Moon. The unit describes a quantity that only exists as a sum across a whole planet's industry.
One zettaoctet equals 1,000 exaoctets, 1,000,000,000,000 gigaoctets, 8 zettabits, or about 0.8470 zebioctets.
The tebioctet is a unit of digital information equal to 1,099,511,627,776 octets, which is 1,024 gibioctets. Its symbol is Tio. It is the binary counterpart of the teraoctet, and at this level the two differ by 10 per cent — the gap that produces the most familiar complaint in consumer computing.
That complaint runs as follows. A drive is sold as one teraoctet, holds exactly one million million octets, and the operating system reports 931 gigaoctets. What it is actually reporting is 0.909 tebioctets, expressed with the wrong label. Nothing is missing from the drive; the number has simply been divided by 1,024 three times and then written with a decimal prefix.
Storage administration lives in this unit. Volume sizes, RAID array capacities, snapshot reserves and quota limits are all quoted in tebioctets by the tools that manage them, because the underlying allocation units are powers of two. A filesystem asked to create a 10-teraoctet volume and one asked to create a 10-tebioctet volume will produce visibly different results.
The difference matters commercially as well as technically. Cloud storage priced per teraoctet and cloud storage priced per tebioctet differ by a tenth in the quantity delivered for the same price, and a contract that does not say which is being used is genuinely ambiguous. Careful procurement documents specify the unit explicitly for exactly this reason.
A tebioctet holds around a quarter of a million photographs, two hundred hours of high-definition video, or the complete text of every book in a large public library many times over. In a household it is more storage than a lifetime of ordinary files will use; in a video production company it is a few days of work.
The correct symbol Tio appears in filesystem tools, in storage array documentation and in standards, and it is worth using even when the audience is unlikely to notice. A figure written with a binary prefix can be converted correctly by anyone who reads it later; one written ambiguously cannot be repaired.
One tebioctet equals 1,099,511,627,776 octets, 1,024 gibioctets, 8 tebibits, or about 1.100 teraoctets.