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.

Gigaoctet per second conversion table