Today, our life is hard to imagine without computers. They are everywhere. The words "bit", "byte", "megabyte" firmly entered our lives. Often ordinary people use them, not knowing what they mean and how they are related.
Bits, kilobits ...
There is an old joke. What is the difference between a normal person and a computer man? The first is sure that in one kilobyte 1000 bytes, and the second - that in kilogram - 1024 grams. And often normal people ask what, in fact, is a joke. Well, let's figure out where the legs grow from and find out how to translate bytes into megabytes or into other multiple units.
Bit is the smallest unit of measurement for 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, etc. A name comes from the English abbreviation bi nary digi t ("binary number") = bit. Also, a “bit" refers to one bit of binary code. In this case, the decimal digit is represented as zero or one, for example, as shown in the table. This is called a "binary number system ."
| Decimal digit | Binary code | Decimal digit | Binary code |
| 0 | 0 | 5 | 101 |
| 1 | 1 | 6 | 110 |
| 2 | 10 | 7 | 111 |
| 3 | eleven | 8 | 1000 |
| 4 | 100 | 9 | 1001 |
As you can see, the numbers 0 and 1 have the same representation, and in the decimal two already two digits - 10. And in the eight - four (1000).
But what is kilobit?
This number system has found the widest application in computer technology. In particular, binary numbers are used to number digital memory cells.
We give an example. The number of all possible addresses on any address bus is two to a certain degree N. Or else, 2 N. 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 the number 2. And then - even more interesting. The number 2 10 = 1024 is very close to 1000. At the same time, a thousand is used as the basis for decimal prefixes. Therefore, 1024 bits came to be called the "kilobit." By analogy with a kilo gram or kilo meter. Recall the joke given above.
Bytes and bits
From computer science the following is known. "Byte" (eng. Byte) is called a unit of storage, as well as processing of digital information. It represents the number of bits processed simultaneously by a computer. This is a classic.
Modern computing systems use an 8-bit byte. Therefore, it can take 256 (2 8 ) different values.
To convert bytes to megabytes, we proceed simply. Arithmetic for the third class: 1 kilobyte = 1024 bytes. Remember about 2 10 ? And 1 Mb = 1024 Kb (i.e. 2 20 = 2 2x10 ) = 1048576 bytes.
Areas of use
Most often, bytes are used in computing systems, and bits are used in information transmission networks. Generally for measuring speed.
We give an example. An Ethernet network provides data rates ranging from 10 Mbps to 1 Gbps. It should also be clarified that, as a rule, a byte is indicated by the letter “B” (or Latin “B”). "Beat" is recorded. The prefix "kilo-" is indicated by the letter "K". It is uppercase, not lowercase. The little “k” is the name of the decimal prefix “kilo-”, i.e. 10 3 = 1000. Now we consider in more detail the following question.
Binary and decimal prefixes
How to translate bytes to megabytes is more or less clear. In early 1999, the well-known organization IEC (International Electrotechnical Commission) introduced binary prefixes to form multiple units of the amount of information. The reason for this was the proximity of the numbers 1024 and 1000. Similarly to the standard decimal prefixes used by the international SI system, binary only differs by replacing the last syllable with "bi" (from Latin binarius - binary). It looks like the table below.
| Console | Abbreviations
adopted by IEC
bytes / bits | Relevant
decimal
console | Value by
multiplies the original
value of the amount of information
|
| kibi | KiB / KiB | kilo (10 3 ) | 1024 or 2 10 |
| mebi | MiB / MiB | mega (10 6 ) | 1048576 or 2 20 |
| bend | GiB / Ghib | gigabyte (10 9 ) | 1073741824 or 2 30 |
| you | TiB / TiBit | tera (10 12 ) | 1099511627776 or 2 40 |
| pebi | PiB / PiBit | peta (10 15 ) | 1125899906842624 or 2 50 |
| exby | EiB (EiB) / Eibit | exa (10 18 ) | 1152921504606846976 or 2 60 |
| zebi | ZiB (ZiB) / Zibit | Zetta (10 21 ) | 1180591620717411303424 or 2 70 |
| yobi | YiB / Yibit | yotta (10 24 ) | 1208925819614629174706176 or 2 80 |
This standard was approved by many countries, but the names entered are not used so often, mainly in written language, but almost never in spoken language. It is believed due to dissonance. Maybe you are right. You must admit that kilobits sound more pleasant than kibibits, and megabytes are better than mebibytes.
The translation of bytes into megabytes is clear. But that is not all. There are still two approaches to the formation of multiple quantities of information. What confuses the question even more is how much is 1 megabyte of bytes.
First approach
In it, the prefixes “kilo”, “mega”, etc. are used as binary for the following cases:
- In file managers and other software with a reduced set file size. For example, the program reports that the size of the audio recording is 10 MB. In the classical way, translating bytes into megabytes, we consider the size, which is 10485760 bytes. In file managers of the latest developments, there is a standard size indication - using the shortened form of binary prefixes, for example, MiB.
- Manufacturers of random access memory devices, flash cards, video memory.
- The volume of a CD-ROM is specified only in binary megabytes.
Second approach
Here, prefixes are used as decimal in the following cases:
- Hard and optical drives. Their volume is given in decimal megabytes. Exception: CD, whose capacity is indicated in binary.
- Informal communication. In this case, the values are roughly rounded. So, for example, about a file with a capacity of 10 million bytes, they can say that it "weighs" 10 megabytes. What do we see here? In this case, bytes were transferred to megabytes not quite correctly, but when communicating, this passes.
- Designation of speeds of telecommunication connections. For example, take the standard 100BASE-TX. In it, 100 Mbit / s corresponds to a data transfer rate of exactly 100 million bits / s. Let's look at a more “nimble” connection with a speed of 10 Gbit / s (standard 10GBASE-X). It corresponds to exactly 10 billion bps. There you go. And not a bit more or less.
But with three-inch floppy disks of 1.44 MB (remember those?) It was even more interesting. Their capacity was indicated in binary decimal megabytes. This was obtained as follows. One such "megabyte" was equal to 1000 KiB, which is approximately 0.977 MiB, but at the same time, 1 KiB was equal to 1024 bytes.
It should be noted that there is a difference between the two options for presenting consoles. And if in the case of a kilobyte it does not exceed 2.4%, then for a megabyte it is already 4.9%, for a gigabyte - 7.4%, and for a terabyte - almost 10%. Naturally, not in favor of a binary representation. That is, byte manufacturers “steal” from us. For example, you buy a 1 TB hard drive. As a person who has studied computer science, you are firmly convinced that it has 1099511627776 bytes. But it turns out - "only" 1000000000000. That is, you have "bitten off" more than 99.5 billion bytes (almost 98 GB). Is it a lot or a little? Roughly - from 40 to 200 feature films, depending on the format. Doesn’t say anything? That is, as written above, the tenth.