Conversion from Yottaoctets per second to Octets per second

Information about the Yottaoctet per second (Yo/s)

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.

Information about the Octet per second (octet/s)

The octet per second is a unit of data transfer rate equal to eight bits per second. Its symbol is octet/s. It is the unit in which software reports transfer speeds, as against the bits per second in which hardware and network services advertise them, and the factor of eight between the two conventions is the source of endless confusion.

The division of labour is consistent once it is understood. Anything describing a physical link — an Ethernet port, a fibre connection, a radio channel, a broadband package — is quoted in bits per second, because bits are what the signalling actually carries. Anything describing a file moving from one place to another is quoted in octets per second, because files are measured in octets.

A download manager that reports 12 megaoctets per second on a connection sold as 100 megabits per second is not disagreeing with the advertisement; it is stating the same rate in the other convention, and the arithmetic between them is a division by eight. Recognising this immediately removes the most common cause of complaint about internet speed.

Individual octets per second appear in the same narrow places as individual bits: deep-space telemetry, low-power sensor links, and the slowest legacy serial connections. A rate of a hundred octets per second would move a page of text in about twenty seconds, which was a normal experience in the 1970s and is unimaginable now.

The unit also underlies the way disc and interface throughput is described. A drive that sustains 500 megaoctets per second is moving four gigabits per second across its interface, and matching the two figures is a routine part of system design: an interface rated in gigabits must be compared with a drive rated in octets, and the factor of eight decides whether one starves the other.

Storage tools reinforce the convention. Every file copy utility, backup program and command-line transfer tool reports in octets per second or its multiples, and every network measurement tool reports in bits per second. A person reading both at once has to keep the conversion in mind, which is exactly what makes the distinction worth stating explicitly.

One octet per second equals 8 bits per second, 0.008 kilobits per second, or 0.001 kilooctets per second.