Megabit
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| SI prefix (rare binary meaning) |
Binary prefix standards from IEC 60027-2 |
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| Name | Symbol | Quantity | Name | Symbol | Quantity |
| kilobit | kb | 103 (210) | kibibit | Kibit | 210 |
| megabit | Mb | 106 (220) | mebibit | Mibit | 220 |
| gigabit | Gb | 109 (230) | gibibit | Gibit | 230 |
| terabit | Tb | 1012 (240) | tebibit | Tibit | 240 |
| petabit | Pb | 1015 (250) | pebibit | Pibit | 250 |
| exabit | Eb | 1018 (260) | exbibit | Eibit | 260 |
| zettabit | Zb | 1021 (270) | zebibit | Zibit | 270 |
| yottabit | Yb | 1024 (280) | yobibit | Yibit | 280 |
The megabit is a unit of information storage, abbreviated Mbit or sometimes Mb.
1 megabit = 106 = 1,000,000 bits which is equal to 125,000 bytes or 125 kilobytes.
The megabit is most commonly used when referring to data transfer rates in network speeds, e.g. a 100 Mbit/s Fast Ethernet connection. In this context, like elsewhere in telecommunications, it always equals 106 bits. Residential high speed internet is often measured in megabits.
A binary counterpart of megabit, useful for measuring RAM and ROM chip capacity, is mebibit.
- Megabits and Videogame Cartridges
In the 16-bit games console era, the 'megabit' (Mbit) became a commonly-used measure of the size (data storage capacity) of games cartridges. The vast majority of SNES / Megadrive (Genesis) games were produced on standard 8Mbit cartridges, although 4Mbit cartridges were not uncommon and, later in the life of these consoles, graphically-intensive titles would appear on 12, 16, even 32Mbit cartridges.
The rule is: 8 bits = 1 byte. Therefore a 4Mbit cartridge had a capacity of 512K, an 8Mbit cartridge held 1MB of data, and so on. It is likely that Nintendo and Sega adopted the 'megabit' terminology for cartridge capacity rather than the more common megabyte for commercial reasons - put simply, the eightfold increase in the numbers helped convince consumers who didn't know their bits from their bytes that they were getting eight times as much game for their money.
It is certain that the SNES Street Fighter II cartridge's proud claim that it came on a 'massive 16Mbit cartridge' sounds more impressive than stating that the whole game weighed in at 2MB, i.e. about the same size as a desktop-sized bitmap image these days.
