Bits Bytes etc
Contents
Units
CraigNDave
https://www.youtube.com/watch?v=9kzCoDFrMGE&list=PLCiOXwirraUCa2MYf_oSM94uvwIGPMZ1q
Computer Science Tutor
https://www.youtube.com/watch?v=Ol3PxSpEeT4&list=PL04uZ7242_M6O_6ITD6ncf7EonVHyBeCm
New Units
Computer Science units are now based around the powers of 10
Powers of 10
For each unit add 3 to the power to go up in powers of 10 for each unit of data for example : 1GB = 10^9 with the power of 10 being 1,000,000,000 bytes However if you subtract three pwoers from 10^9 then 10^6 = 1,000,000 bytes
The Bit
The Bit is a single binary digit used in computing and is represented using either a 1 or 0. The two values of a single digit act as an On or Off function or True/False and putting them together can result in unique functions as 1 digit can control one variable and another digit can control an entirely different variable. By putting multiple bits together functions become more complex and have more outcomes as if you set one value to true it can lead to another set of values different to what you would get if it was set to false. Putting 8 of theses bits together is called a byte
The Byte
A byte is made up of 8 bits, and larger amounts of data are based around the value of a byte (e.g Gigabyte being 1,000,000,000 bytes). A single byte represents one binary number, as it is made up of a total of 8 1's and 0's. A single byte can also represent a single character, such as the letter B.
Kilo Byte
A Kilo Byte is 1000 bytes. It is also a multiple of the byte unit with the prefix (kB).
Mega Byte
A Mega Byte is 1000 Kilo Bytes, thus is 1000000 Bytes. In Base 10 the prefix Mega is 10^6.
Giga Byte
1 giga byte (1Gb) is 1000 megabytes and also 1 Gigabyte (G / GB) = 10^9 bytes = 1,000,000,000 bytes
Tera Byte
1 TeraByte = 1,000 GigaByte, 10^12 bytes
Peta Byte
Symbol PB Power 10^15
Exa Byte
Symbol: EB Power: 10^18 Bytes: 1,000,000,000,000,000,000
Zetta Byte
Symbol: ZB Power: 10^21 Bytes: 1,000,000,000,000,000,000,000
Yotta Byte
Yottabyte (YB) is a unit of digital information that equals to one septillion (10^24).
Old Units
Units based around powers of 2, according to the spec you don't need to know these
Powers of 2
A power of two is a number of the form 2n where n is an integer. (e.g. 7).
| Power of 2 | Equivalent |
|---|---|
| 20 = 1 | (Anything to the power of itself is always 1) |
| 21 = 2 | 2x1 = 2 |
| 23 = 4 | 2x2 = 4 |
| 24 = 8 | 2x2x2 = 8 |
| 25 = 16 | 2x2x2x2 = 16 |
Etc.
Kibi Byte
A kibibyte is a multiple of the unit byte, with the binary prefix 'kibi' meaning 2 to the power of 10 or 1024 bytes.
Therefore meaning 1 kibibyte is 1024 bytes.
The unit symbol for a kibibyte is KiB.
Mebi Byte
The binary prefix mebi means 2^20; therefore one mebibyte is equal to 1048576bytes = 1024 kibibytes.
The unit symbol for the mebibyte is MiB.
1 MiB = 2^20 bytes = 1024 kibibytes = 1048576bytes
Gibi Byte
1 GiB is equal to 2^30. (Two to the power of thirty)
1 GB = 0.931323 GiB
Tebi Byte
A tebibyte is a unit of data storage that equals 2 to the 40th power, or 1,099,511,627,776 bytes. While a terabyte can be estimated as 10^12 or 1,000,000,000,000 bytes, a tebibyte is exactly 1,099,511,627,776 bytes.
Pebi Byte
A Pebi Byte is a multiple of the unit byte, used for digital information.
The prefix for pebi is Pi and the prefix for pebibyte is PiB 1,125,899,906,842,624 bytes and is equivalent to 1024 tebibytes or 1 pebibyte.
to get from pebibytes to bits, you can do: pebibytes times 2 to the power of 50 (PiB x 2^50) or pebibytes times 1024 to the power of 5 (PiB x 1024^5) and to get from bits to pebibytes, you can do: bits divided by 2 to the power of 50 (bits / 2^50) or bits times 1024 to the power of 5 (bits / 1024^5)
Exbi Byte
2^60
Zebi Byte
2^70
Yobi Byte
2^80
