Orders of magnitude (data)

An order of magnitude is a factor of ten. A quantity growing by four orders of magnitude implies it has grown by a factor of 10,000 or 104.

This article presents a list of multiples, sorted by orders of magnitude, for digital information storage measured in bits.

The byte is a common unit of measurement of information (kilobyte, kibibyte, megabyte, mebibyte, gigabyte, gibibyte,  terabyte, tebibyte, etc). For the purpose of this article, a byte is a group of 8 bits (octet), a nibble is a group of four bits. Historically, both assumptions have not always been true.

The decimal SI prefixes kilo, mega, giga, tera, etc, are powers of 103 = 1000. The binary prefixes kibi, mebi, gibi, tebi, etc respectively refer to the corresponding power of 210 = 1024. In casual usage, when 1024 is a close enough approximation of 1000, the two corresponding prefixes are equivalent.

Note: this page mixes between two kinds of entropies:
 Entropy (information theory), such as the amount of information that can be stored in DNA
 Entropy (thermodynamics), such as entropy increase of 1 mole of water
These two definitions are not entirely equivalent, see Entropy in thermodynamics and information theory.

For comparison, the Avogadro constant is  entities per mole, based upon the number of atoms in 12 grams of carbon-12 isotope.

In 2012, some hard disks used ~984,573 atoms to store each bit. In January 2012, IBM researchers announced they compressed 1 bit in 12 atoms using antiferromagnetism and a scanning tunneling microscope with iron and copper atoms. This could mean a practical jump from a  disk to a  disk.

See also 
 SI prefix
 E1 series of preferred numbers
 Binary prefix
 Data rate units
 Orders of magnitude (entropy)
 Unit prefix#Unofficial prefixes

References 

Data