| Gibioctets per second (Gio/s) | Yottaoctets per second (Yo/s) |
|---|---|
| 1 Gibioctet per second | 1.073741824 × 10-15 Yo/s |
| 2 Gibioctets per second | 2.147483648 × 10-15 Yo/s |
| 3 Gibioctets per second | 3.221225472 × 10-15 Yo/s |
| 4 Gibioctets per second | 4.294967296 × 10-15 Yo/s |
| 5 Gibioctets per second | 5.36870912 × 10-15 Yo/s |
| 10 Gibioctets per second | 1.073741824 × 10-14 Yo/s |
| 20 Gibioctets per second | 2.147483648 × 10-14 Yo/s |
| 25 Gibioctets per second | 2.68435456 × 10-14 Yo/s |
| 50 Gibioctets per second | 5.36870912 × 10-14 Yo/s |
| 100 Gibioctets per second | 1.073741824 × 10-13 Yo/s |
| Reference | Gibioctets per second (Gio/s) | Yottaoctets per second (Yo/s) |
|---|---|---|
| A dial-up modem | 0.00000651926 Gio/s | 7 × 10-21 Yo/s |
| Typical home broadband | 0.0116415 Gio/s | 1.25 × 10-17 Yo/s |
| Gigabit Ethernet | 0.116415 Gio/s | 1.25 × 10-16 Yo/s |
| Streaming a 4K film | 0.00291038 Gio/s | 3.125 × 10-18 Yo/s |
The gibioctet per second is a unit of data transfer rate equal to 1,073,741,824 octets per second, which is 1,024 mebioctets per second. Its symbol is Gio/s. It is the unit of memory bandwidth and of the fastest storage interfaces, and the binary counterpart of the gigaoctet per second, from which it differs by 7.4 per cent.
Memory is where the unit belongs most naturally. A memory channel transfers a fixed number of octets per clock cycle, and that number is a power of two, so the resulting bandwidth is a binary multiple of the clock frequency. A machine with several channels reaches tens of gibioctets per second, and an accelerator with stacked memory reaches thousands.
Storage has caught up. A fast solid-state drive on the current interface sustains several gibioctets per second, which means that for the first time the drive and the memory are within an order of magnitude of each other. That convergence has changed how software is written: the old assumption that reading from disc is thousands of times slower than reading from memory no longer holds.
The unit appears in benchmark output, in system monitoring displays and in the specifications of processor interconnects. All of these count in binary because the structures they measure are binary, and reporting the result with a decimal prefix would introduce a seven per cent error for the sake of a familiar-looking label.
For a sense of what the rate means, one gibioctet per second copies a two-gigaoctet film in under two seconds and fills a one-teraoctet drive in about a quarter of an hour. Anything at this speed is faster than every external connection in an ordinary building, so the limiting factor moves inside the machine.
The distinction from the decimal unit matters most in procurement and capacity planning. A specification that requires 10 gigaoctets per second and a system that delivers 10 gibioctets per second are not the same, and the difference of 7.4 per cent is the sort of margin that decides whether a design meets its requirement.
One gibioctet per second equals 1,073,741,824 octets per second, 1,024 mebioctets per second, or about 1.074 gigaoctets per second.
The yottaoctet per second is a unit of data transfer rate equal to a thousand zettaoctets per second, or eight yottabits per second. Its symbol is Yo/s. It is the largest transfer rate the metric system named for thirty years, and it stands at the point where the question stops being one of engineering and becomes one of physics.
The physical limits are real and can be stated. Any communication channel has a capacity set by its bandwidth and its signal-to-noise ratio, a result Claude Shannon proved in 1948. Pushing a rate higher means using more bandwidth, more power, or more parallel channels, and each of those has a cost that grows without limit as the rate does.
Energy sets the sharpest bound. Thermodynamics requires a minimum energy to distinguish one state from another at a given temperature, and although practical systems are many orders of magnitude above that floor, the floor is not zero. At a yottaoctet per second even the theoretical minimum becomes a substantial power, and every real system multiplies it by a large factor.
There is also a limit from the medium itself. A single optical fibre has a capacity ceiling set by non-linear effects in the glass, which grow with the light power carried, so raising the power eventually degrades the signal rather than improving it. Reaching a yottaoctet per second would require something like a hundred billion fibres running at today's records simultaneously, which is a construction problem rather than a communication one.
None of this makes the unit meaningless. It is properly defined, it converts by the same rule as every other, and it appears in discussions of theoretical limits and in complete tables of the prefix system. A measurement system that stopped naming quantities at the point where engineering stops would be less useful, not more.
Since 2022 the metric system has had ronna and quetta above yotta, so this is no longer the top of the ladder. That extension was driven by data quantities rather than by rates, and nothing in transmission has yet given a reason to write a rate above this one.
One yottaoctet per second equals 1,000 zettaoctets per second, 8 yottabits per second, or about 0.8272 yobioctets per second.