Megabit


Megabit
v · d · e
Multiples of bits
SI decimal prefixes IEC binary prefixes
Name
(Symbol)
Value Name
(Symbol)
Value
kilobit (kbit) 103 kibibit (Kibit) 210 = 1.024 × 103
megabit (Mbit) 106 mebibit (Mibit) 220 ≈ 1.049 × 106
gigabit (Gbit) 109 gibibit (Gibit) 230 ≈ 1.074 × 109
terabit (Tbit) 1012 tebibit (Tibit) 240 ≈ 1.100 × 1012
petabit (Pbit) 1015 pebibit (Pibit) 250 ≈ 1.126 × 1015
exabit (Ebit) 1018 exbibit (Eibit) 260 ≈ 1.153 × 1018
zettabit (Zbit) 1021 zebibit (Zibit) 270 ≈ 1.181 × 1021
yottabit (Ybit) 1024 yobibit (Yibit) 280 ≈ 1.209 × 1024
See also: Nibble · Byte · Multiples of bytes
Orders of magnitude of data

The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega (symbol M) is defined in the International System of Units (SI) as a multiplier of 106 (1 million),[1] and therefore

1 megabit = 106bits = 1000000bits = 1000 kilobits.

The megabit has the unit symbol Mbit or Mb.

Using the common byte size of 8 bits, 1 Mbit is roughly equal to 125 kilobytes (kB) or approximately 122 kibibytes (KiB).

The megabit is closely related to the mebibit, a unit multiple derived from the binary prefix mebi (symbol Mi) of the same order of magnitude,[2] which is equal to 220bits = 1048576bits, or approximately 5% larger than the megabit. Despite the definitions of these new prefixes for binary-based quantities of storage by international standards organizations, memory semiconductor chips are still marketed using the metric prefix names to designate binary multiples.

The megabit is widely used when referring to data transfer rates of computer networks or telecommunications systems. Network transfer rates and download speeds often use the megabit as the amount transferred per time unit, e.g., a 100 Mbit/s (megabit per second) Fast-Ethernet connection, or a 10 Mbit/s Internet access service, whereas the sizes of data units (files) transferred over these networks are often measured in megabytes. To achieve a transfer rate of one megabyte (1000kB) per second one needs a network connection with a transfer rate of eight megabits per second. This can be confusing for internet users assuming the values are in kilobytes and megabytes per second. If one goes to buy a 2 megabit per second internet plan, they are really only getting a 250 kilobyte per second plan.

Usage conventions

  • In Telecommunications, use of the correct SI definition of the unit is standard.
  • Standard industry practice in RAM and ROM manufacture has been to use the Mb abbreviation in reference to the binary interpretation of the megabit. For example, a single discrete DDR3 chip specified at 512 Mb invariably contains 229 bits = 536870912bits = 512 Mibit of storage,[3] or 671088648-bit bytes, variously referred to as either 64 mebibytes or 64 (binary) megabytes.
  • During the 16-bit game console era, the megabit was a commonly used measure of the size (computer data storage capacity) of game cartridges. This size represented one mebibit (Mibit). The vast majority of SNES and Mega Drive (Genesis) games were produced on 8 megabit cartridges, although other sizes, such as 4, 12, 16, 24, 32, and 48 megabit cartridges appeared. The standard rule is 8 bits to a 1 byte. Therefore, a 4 megabit cartridge had a capacity of 512 KiB, and a 8 megabit cartridge held 1 MiB of data. Also meaning the 16 bit era was 8 megabits per cartridge.

See also

References


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Look at other dictionaries:

  • Megabit — Mégabit Un mégabit (symbole : Mb ou Mbit) est une unité de mesure en informatique. Un mégabit vaut un million de bits (parfois 1 048 576 = 220). Voir aussi Megabyte Préfixe binaire Portail de l’informatique Ce doc …   Wikipédia en Français

  • megabit — megabít s. m., pl. megabíţi Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  MEGABÍT s. m. (cib.) unitate de măsură a informaţiilor, de un milion de biţi. (< fr. mégabit) Trimis de raduborza, 15.09.2007. Sursa: MDN …   Dicționar Român

  • mégabit — ● mégabit nom masculin Unité de mesure (symbole Mbit ou Mb), équivalant à 220 bits. mégabit n. m. INFORM Unité de mesure valant 1 million de bits …   Encyclopédie Universelle

  • megabit — mȅgabit m <N mn ovi> DEFINICIJA int. jedinica za mjerenje količine podataka koja se prenosi komunikacijskim kanalom, iznosi približno milijun bitova [megabit u sekundi oznaka Mbps] ETIMOLOGIJA mega (1b) + v. bit …   Hrvatski jezični portal

  • megabit — UK US /ˈmeɡəbɪt/ noun [C] IT ► a unit for measuring the speed at which information is sent between computers, equal to one million bits: »The network offers speeds of 100 megabits per second …   Financial and business terms

  • Mégabit — Pour les articles homonymes, voir Bit (homonymie).  Ne doit pas être confondu avec byte …   Wikipédia en Français

  • Megabit — Vielfache von Bit SI Präfixe Binärpräfixe Name Symbol Bedeutung Name Symbol Bedeutung Kilobit kbit 103 bit Kibibit Kibit 210 bit Megabit Mbit 106 bit Meb …   Deutsch Wikipedia

  • Megabit — Unidades básicas de información (en bytes) Prefijos del Sistema Internacional Prefijo binario Múltiplo (Símbolo) Estándar SI Binario Múltiplo (Símbolo) Valor kilobyte (kB) 103 210 …   Wikipedia Español

  • megabit — UK [ˈmeɡəˌbɪt] / US noun [countable] Word forms megabit : singular megabit plural megabits computing a million bits (= the smallest unit of information that can be used by a computer) …   English dictionary

  • Megabit — El Megabit (Mbit o Mb) es una unidad de medida de información muy utilizada en las transmisiones de datos de forma telemática. Representa un millón de bits (1.000.000) y con frecuencia se le confunde con el Megabyte que equivale a 220 (1 048 576) …   Enciclopedia Universal


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