| Mebioctets per second (Mio/s) | Exbibits per second (Eibit/s) |
|---|---|
| 1 Mebioctet per second | 7.27595761418 × 10-12 Eibit/s |
| 2 Mebioctets per second | 1.45519152284 × 10-11 Eibit/s |
| 3 Mebioctets per second | 2.18278728426 × 10-11 Eibit/s |
| 4 Mebioctets per second | 2.91038304567 × 10-11 Eibit/s |
| 5 Mebioctets per second | 3.63797880709 × 10-11 Eibit/s |
| 10 Mebioctets per second | 7.27595761418 × 10-11 Eibit/s |
| 20 Mebioctets per second | 1.45519152284 × 10-10 Eibit/s |
| 25 Mebioctets per second | 1.81898940355 × 10-10 Eibit/s |
| 50 Mebioctets per second | 3.63797880709 × 10-10 Eibit/s |
| 100 Mebioctets per second | 7.27595761418 × 10-10 Eibit/s |
| Reference | Mebioctets per second (Mio/s) | Exbibits per second (Eibit/s) |
|---|---|---|
| A dial-up modem | 0.00667572 Mio/s | 4.85723 × 10-14 Eibit/s |
| Typical home broadband | 11.9209 Mio/s | 8.67362 × 10-11 Eibit/s |
| Gigabit Ethernet | 119.209 Mio/s | 8.67362 × 10-10 Eibit/s |
| Streaming a 4K film | 2.98023 Mio/s | 2.1684 × 10-11 Eibit/s |
The mebioctet per second is a unit of data transfer rate equal to 1,048,576 octets per second, which is 1,024 kibioctets per second. Its symbol is Mio/s. It is the unit that disc benchmarks, copy tools and backup programs report in, and one of the few binary units most people see regularly without noticing.
Storage measurement produces it naturally. A benchmark writes and reads blocks whose size is a power of two, times the operation, and divides. The result is a binary rate, and reporting it as such preserves the arithmetic. A tool that converted to decimal megaoctets would introduce a 4.9 per cent adjustment for no purpose other than to match a marketing convention.
That five per cent is exactly where the two conventions diverge visibly for consumers. A drive advertised at 550 megaoctets per second and measured at 524 mebioctets per second is performing precisely as claimed; the numbers differ only because one is decimal and the other binary. A great deal of complaint about storage performance is this arithmetic misread as a shortfall.
For everyday sizes, one mebioctet per second copies a photograph in three seconds and a two-gigaoctet film in about half an hour. Modern drives run hundreds or thousands of times faster, so the unit is now the resolution at which small differences are reported rather than the scale of the whole figure.
The unit also appears in memory and cache measurements, in database throughput reports and in the output of the low-level commands that write disc images. All of these count in binary blocks because the underlying structures are binary, and all of them report in mebioctets per second because that is what the count divided by the time actually gives.
The habit of writing the lowercase i is worth keeping. It costs one character and it tells a later reader which of two conventions produced the number, which is information that cannot be recovered from context once it has been left out.
One mebioctet per second equals 1,048,576 octets per second, 1,024 kibioctets per second, or about 1.049 megaoctets per second.
The exbibit per second is a unit of data transfer rate equal to two to the sixtieth power bits per second, which is 1,024 pebibits per second. Its symbol is Eibit/s. It is the binary counterpart of the exabit per second, and the two differ by 15.3 per cent.
That fifteen per cent is more than the margin most engineering work allows anywhere. A quantity stated in the wrong convention at this level is not slightly imprecise but plainly wrong, and no amount of context recovers the intended figure once it has been written ambiguously. This is the situation the IEC prefixes were introduced to prevent.
No physical link approaches this rate. The unit describes aggregates: the total instantaneous traffic of the whole internet is roughly an exabit per second, so a binary exbibit per second is fifteen per cent more than everything moving on every network on the planet at a given moment.
Where a binary figure of this size arises naturally is in address arithmetic rather than in transmission. Two to the sixtieth is a number that appears throughout the design of 64-bit systems, and any rate derived from filling or traversing such an address space in a fixed time is naturally binary. Those calculations are theoretical, but they are the reason the unit is defined rather than left unnamed.
In octets an exbibit per second is 144,115,188,075,855,872, or 128 pebioctets per second. That is more storage moved per second than the world manufactures in several years, which is a way of saying that no source and no destination for such a flow could exist.
For a converter the treatment is mechanical and must be exact. Eibit/s and Ebit/s differ by an eighth, and a tool that treats them as interchangeable has introduced an error larger than the difference between many neighbouring units. The lowercase i is not decoration.
One exbibit per second equals 1,024 pebibits per second, 144,115,188,075,855,872 octets per second, or about 1.153 exabits per second.