How to translate bytes into megabytes and back?

today is difficult to imagine our life without computers.They are everywhere.The words "bit", "byte", "megabytes" have become part of our lives.Most ordinary people use them without knowing what they mean, and how interconnected.

bits, kilobits ...

There is an old anecdote.What is the difference between a normal person and a computer specialist?The first sure that one kilobyte 1000 bytes, and the second - in kilogram - 1024 grams.And normal people often ask, and what, in fact, a joke.Well, we shall understand where his feet are growing, and find out how to translate bytes into megabytes, or other multiple units.

bit - the smallest unit of binary information.More precisely, its quantity.This refers to information about one of the two states of the object.For example, there is a signal / no signal, true / false, 1/0, and so on. D. There is a name from the English abbreviation bi nary digi t ("binary") = bit.Also, "bit" refers to one digit of the binary code.In this case, a decimal digit is represented as a zero or one, for example as shown in the table.This is called a "binary system".

As you can see, the numbers 0 and1 have the same idea, but in the two-man team for two decimal digit - 10. And in the eight - four (1000).

And what a kilobit?

most widely used this number system found in computer technology.In particular, binary numbers are used for numbering the digital memory cells.

Here is an example.The number of all possible addresses to any address bus is the number two in some degree N. Or else - 2N.Here, N denotes the number of bits of the bus.What do we see?The number of cells in the memory chip is equal to one degree or another of 2. And then - even more interesting.Number 210 = 1024 is very close to 1000. At the same time, thousands of used as the basis for the decimal prefixes.Thus 1024 bits became known as "kilobits".By analogy with kilo gram or kilo meter.I recall the anecdote, shown above.

bytes and bits

From informatics know the following."Byte" (eng. Byte) called storage unit, and the processing of digital information.It represents the number of bits simultaneously processed by a computer.This is a classic.

Modern computer systems use byte consisting of 8 bits.Therefore, it may take 256 (28) different values.

To convert bytes into megabytes, just act.Arithmetic for the third class: 1 kilobyte = 1024 bytes.I remember about 210?A 1 MB = 1024 KB (t. S. 220 = 22h10) = 1,048,576 bytes.

Applications

Most often the bytes used in computer systems, and bits - networks of information transfer.Generally, for velocity measurement.

Here is an example.Ethernet network provides data transfer speeds in the range of 10 Mbit / s to 1 Gb / s.More should be noted that, as a rule, the byte indicated by the letter "B" (or Latin «B»)."Bit" and recorded.The prefix "kilo" is designated by the letter "K".It is a capital rather than horizontal.Little "K" is written the name of the decimal prefix "kilo", ie103 = 1000. Now consider in more detail the following question.

binary and decimal prefixes

How to translate bytes into megabytes, more or less clear.In early 1999, the well-known organization IEC (International Electrotechnical Commission) put into circulation binary prefix to form multiple units of quantity information.The reason for this was the proximity of the numbers 1024 and 1000. Similarly, the standard decimal prefixes used by the international system of SI binary differ only by the replacement of the last syllable in the "bi" (from the Latin binarius - binary).It looks like this, as shown in the table below.

The standard adopted by many countries, but the entered names are used less frequently, mainly in writing and orally - almost never.It is believed that because of the cacophony.Perhaps so.You agree that kilobits sounds nicer than kibibit and megabytes better than mebibytes.

Translation bytes megabytes clear.But that's not all.Until now, there are two approaches to the formation of multiple values ​​the amount of information.What further complicates the question of how many are in the 1 megabyte byte.

first approach

In it the prefix "kilo," "mega" and so on. D. Are used as a binary for the following cases:

• in the file manager, and other software in the abbreviated file size setting.For example, the program reports that the record size is 10 MB.The classic way to transfer bytes in megabytes, consider size, which is 10485760 bytes.The file managers of recent developments meets the standard dimensioning - using the short form of binary attachments, such MiB (MiB).
• Manufacturers random access memory, flash cards, video memory.
• volume CD-ROM is specified only in binary megabytes.

second approach

There decimal prefixes are used as in the following cases:

• Hard and optical disk drives.Their volume of lead in decimal megabytes.Exception: CD, whose capacity is indicated in binary.
• informal communication.In this case, the roughly rounded off.For example, a file about 10 million bytes volume can say that it "weighs" 10 megabytes.What do we see here?In this case, the bytes in megabytes transferred is not entirely correct, but it takes communication.
• speed symbol telecom connections.For example, take the standard 100BASE-TX.In it 100 Mbit / s data rate corresponds exactly 100 million bits / s.Let's look at a more "nimble" connection to 10 Gbit / s (standard 10GBASE-X).It corresponds to exactly 10 billion bits / sec.That's it.Not a bit more or less.

But with three-inch floppy disks 1.44 MB (remember those?), It was even more interesting.Their capacity is indicated in BCD megabytes.It is prepared as follows.One such "megabytes" was KiB is 1000, which is approximately 0.977 MiB, but at the same time KiB 1 equaled 1024 bytes.

should be noted that there is a difference between these two options submission consoles.And if in the case of kilobytes it does not exceed 2.4%, then a megabyte is already 4.9% for GB - 7.4% and terabytes - nearly 10%.Naturally, not in favor of the binary representation.E. "Steal" our manufacturers bytes.For example, buying a hard drive capacity of 1 TB.As someone who has studied computer science, you piously believe that there 1099511627776 bytes.And it turns out - "only" 1000000000000. That is, you have "bitten off" more than 99.5 billion bytes (almost 98 GB).A lot or a little?Coarse - 40 to 200 of full-length films, depending on the format.Not about what does not speak?E., As described above, the tenth part.