| Tebioctets (Tio) | Petabits (Pbit) |
|---|---|
| 1 Tebioctet | 0.00879609302221 Pbit |
| 2 Tebioctets | 0.0175921860444 Pbit |
| 3 Tebioctets | 0.0263882790666 Pbit |
| 4 Tebioctets | 0.0351843720888 Pbit |
| 5 Tebioctets | 0.043980465111 Pbit |
| 10 Tebioctets | 0.0879609302221 Pbit |
| 20 Tebioctets | 0.175921860444 Pbit |
| 25 Tebioctets | 0.219902325555 Pbit |
| 50 Tebioctets | 0.43980465111 Pbit |
| 100 Tebioctets | 0.879609302221 Pbit |
| Reference | Tebioctets (Tio) | Petabits (Pbit) |
|---|---|---|
| A plain text message (160 characters) | 1.45519 × 10-10 Tio | 1.28 × 10-12 Pbit |
| A three-minute MP3 | 0.00000272848 Tio | 0.000000024 Pbit |
| A smartphone photo | 0.00000363798 Tio | 0.000000032 Pbit |
| A high-definition film | 0.00363798 Tio | 0.000032 Pbit |
| A dual-layer Blu-ray disc | 0.0454747 Tio | 0.0004 Pbit |
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.
The petabit is a unit of digital information equal to a thousand terabits, or a million billion bits. Its symbol is Pbit. It sits at the boundary between quantities that are routinely deployed and quantities that still belong to research laboratories and to totals aggregated across whole networks.
A petabit is 125 teraoctets. That is the storage of roughly a hundred and twenty-five large consumer hard drives, or in more everyday terms about thirty thousand hours of high-definition video — three and a half years of continuous viewing. No single device holds a petabit; the figure describes systems rather than objects.
The most striking use of the unit is in optical transmission records. Research groups in Japan, the Netherlands and elsewhere have carried more than a petabit per second down a single strand of fibre, achieved by combining multi-core fibre — several light-guiding paths inside one cladding — with hundreds of separate wavelengths and advanced modulation. Those results run over tens of kilometres in the laboratory, not the thousands of kilometres a working sea cable must cross.
At the network level the petabit describes aggregate capacity. The total interconnect capacity of a large data centre, the combined capacity of all cables landing on a continent, and the peak throughput of the largest content networks are all quoted in petabits per second. These are sums over many links rather than the rating of any one of them.
Storage systems reach petabit scale too, though they are always labelled in octets. A large scientific archive holding a hundred petaoctets is holding eight hundred petabits, and facilities of that size exist for genomics, particle physics and astronomical survey data. The particle detectors at CERN discard the vast majority of what they see precisely because keeping it would exceed even these capacities.
The prefix peta comes from the Greek for five, because a petabit is a thousand raised to the fifth power in bits. That naming pattern continues upward with exa for six and zetta for seven, so the ladder above the petabit is regular and easy to extend.
One petabit equals 1,000,000,000,000,000 bits, 1,000 terabits, 125 teraoctets, or about 0.8882 pebibits.