Conversion from 100 Petabits per second to Exaoctets per second

Information about the Petabit per second (Pbit/s)

The petabit per second is a unit of data transfer rate equal to a thousand terabits per second. Its symbol is Pbit/s. It marks the frontier of optical transmission research: the rate at which laboratories have carried data down a single strand of glass, and which no deployed system yet approaches.

The records were set by combining three techniques. Multi-core fibre puts several separate light-guiding paths inside one cladding, so that a single strand behaves like a bundle. Wavelength division multiplexing runs hundreds of distinct colours down each of those cores. Advanced modulation encodes many bits into each pulse. Multiplying the three together is what reaches a petabit per second.

Such demonstrations run over tens of kilometres of fibre in controlled conditions, not the thousands of kilometres a working sea cable must span. Distance is the hard part: signals attenuate, dispersion smears pulses together, and non-linear effects in the glass grow with power. Every kilometre added makes the same rate harder to sustain, which is why deployed cables sit two orders of magnitude below the laboratory record.

In octets a petabit per second is 125 teraoctets per second, which is roughly the storage of a hundred and twenty-five large hard drives moved every second. Nothing at either end of such a link could produce or absorb data at that rate; the figure describes the medium's capacity rather than any use of it.

At the network level the unit is used for aggregates. The total interconnect capacity of a very large data centre, the summed capacity of all the cables landing on a continent, and the peak traffic of the largest content networks are quoted in petabits per second. These are sums over thousands of links, not the rating of any one.

The trajectory is worth noting. Transoceanic capacity has grown by roughly a factor of ten every seven or eight years for several decades, driven almost entirely by better electronics and better coding rather than by more glass. If that continues, the petabit per second will describe a working cable within a generation.

One petabit per second equals 1,000 terabits per second, 125 teraoctets per second, or about 0.8882 pebibits per second.

Information about the Exaoctet per second (Eo/s)

The exaoctet per second is a unit of data transfer rate equal to a thousand petaoctets per second, or eight exabits per second. Its symbol is Eo/s. Nothing built runs at this rate: it is about eight times the total traffic of the entire internet, counted across every network on the planet at once.

The unit is useful mainly for thought experiments about limits. If every hard drive and flash chip manufactured in a year were read simultaneously at full speed, the combined rate would be in this range. So would the total output of every camera sensor in every phone on Earth if they all recorded at once. These are sums over the whole world's hardware, not rates any system experiences.

There is one situation in which very large data volumes really do move faster than any network, and it puts the unit in perspective. Physically shipping a container of hard drives across an ocean transfers more data per second, averaged over the journey, than any cable. A shipping container holding a few exaoctets crossing the Atlantic in a week works out to several gigaoctets per second, and a truck of drives driven across a city beats almost any local link.

That calculation is not a joke; cloud providers offer it as a service. When a customer needs to move petaoctets into a data centre, the provider ships a lorry full of storage rather than attempting the transfer over a network, because the network would take months. The bandwidth of a vehicle is enormous, though its latency is measured in days.

For the unit itself, an exaoctet per second is 125 petaoctets per second, and it would transfer the world's entire stock of stored data — a few hundred zettaoctets — in about a week of continuous running. No mechanism exists to feed such a link, and none is being designed.

A converter must nevertheless handle the unit, because it appears in aggregate capacity models, in academic papers on the theoretical limits of communication, and in any table that lists the metric prefixes completely. A quantity does not need a use for its name to be well formed.

One exaoctet per second equals 1,000 petaoctets per second, 8 exabits per second, or about 0.8674 exbioctets per second.