Conversion from 5 Exabits per second to Gigaoctets per second

Information about the Exabit per second (Ebit/s)

The exabit per second is a unit of data transfer rate equal to a thousand petabits per second. Its symbol is Ebit/s. No link, no cable and no exchange point runs at this rate; the unit describes the internet as a whole, or a large part of it, at a single instant.

Global internet traffic can be expressed this way. Worldwide traffic of several hundred exaoctets a month works out to roughly one exabit per second on average, and peak hours run higher. That figure is the sum of every packet moving on every network on the planet, and it is the only quantity anyone routinely describes at this scale.

An exabit per second is 125 petaoctets per second. Nothing generates data at that rate in one place; the number is an aggregate of billions of separate flows, most of them tiny. A single video stream is a few megabits per second, so an exabit per second is on the order of a hundred million such streams running at once.

The composition of that traffic is dominated by video. Streaming services account for the largest share, followed by social platforms, software updates and cloud synchronisation. Ordinary web browsing and messaging, which people think of as the internet, are a small fraction of the total by volume even though they occupy most of the attention.

The unit also appears in projections of aggregate capacity. The total installed capacity of all submarine cables, if every wavelength on every fibre pair were lit and used simultaneously, is in the exabit-per-second range. Actual utilisation is far below that, because capacity is built ahead of demand and because routes must carry each other's traffic when a cable fails.

The prefix exa is a thousand to the sixth power. It was adopted in 1975, when nobody expected it to describe anything but astronomical quantities, and it now describes the working throughput of a communications system built by human beings. The interval between definition and everyday use was about forty years.

One exabit per second equals 1,000 petabits per second, 125 petaoctets per second, or about 0.8674 exbibits per second.

Information about the Gigaoctet per second (Go/s)

The gigaoctet per second is a unit of data transfer rate equal to one thousand million octets per second, or eight gigabits per second. Its symbol is Go/s. It is the unit of the fastest storage devices and of the buses inside a computer, where data moves between processor, memory and drive.

Solid-state drives on the current interface reach 3 to 14 gigaoctets per second, depending on the number of lanes they use and the generation of the bus. Each lane of the peripheral interconnect provides roughly 2 gigaoctets per second at the current generation, and a drive typically uses four of them. Doubling the generation doubles the rate, which is why the figures have risen so steadily.

Main memory is faster still. A modern memory channel delivers 30 to 60 gigaoctets per second, and a machine with several channels reaches hundreds. Graphics processors, which must feed thousands of arithmetic units at once, use memory with bandwidths measured in thousands of gigaoctets per second, at which point the unit gives way to teraoctets.

That hierarchy is what determines how a program performs. A processor can execute far more operations per second than memory can supply data for, so most fast software is written to keep data in the small fast caches rather than to fetch it repeatedly from main memory. The whole discipline of performance engineering rests on the size of these differences.

For everyday comparison, one gigaoctet per second copies a two-gigaoctet film in two seconds, and fills a one-teraoctet drive in about seventeen minutes. That is faster than the network in almost every home and faster than most external connections, so at this rate the bottleneck moves back to whatever is at the other end.

The unit also describes network links in the data centre. A ten-gigabit connection is 1.25 gigaoctets per second, a hundred-gigabit connection 12.5, and both are common between servers. Comparing a storage figure in octets with a network figure in bits requires the factor of eight, and forgetting it is how equipment gets mismatched.

One gigaoctet per second equals 1,000,000,000 octets per second, 8 gigabits per second, or about 0.9313 gibioctets per second.