# International Units : MB/GB or MiB/GiB

New IEC prefixes and descriptions for binary multiples were introduced in 1998/99

The prefixes (M,G,T,P...) for decimal numbers are unchanged.
The descriptive terms (Mega, Giga,Tera,Peta..) are also unchanged

The prefixes (Mi,Gi,Ti,Pi,Ei) are now used to indicate Power of 2 (binary) numbers.
The new descriptive terms are (mebi,gibi,tebi,pebi,exbi).

 Decimal Data Transfer,HD, DVD ( K,M,G,T,P,E ) Power of 2 (binary) Data Files,RAM,CD ( Ki,Mi,Gi,Ti,Pi,Ei ) K kilo 10^3 = 1000 Ki = 16^2.5 = 2^10 =1,024 M mega 10^6 =1000,000 Mi = 16^5 = 2^20 =1,048,576 G giga 10^9 =1000,000,000 Gi = 16^7.5 = 2^30 =1,073,741,824 T tera: 10^12 =1000,000,000,000 Te = 16^10 = 2^40 =1,099,511,627,776 P peta: 10^15 =1000,000,000,000,000 Pe = 16^12.5 = 2^50 E exa: 10^18 =1000,000,000,000,000,000 Ex = 16^15 = 2^60 Z zetta: 10^21 Ze = 16^17.5 = 2^70 Y yotta: 10^24 Yo = 16^20 = 2^80

Any of the above can be entered directly into a spreadsheet e.g. = 2^30 will give 1 GiB

Examples

A 100 megabit network has a capacity of 100,000,000 bits per second.
If the Data Transfer packets are 64 KB = 65,536 Bytes = 524,288 bits (bits = Bytes x 8 )

So in this example the network would transfer around 200 packets per second.

“Failure of the NASA Mars Climate Orbiter occurred because the flight system software was written using metric units, while the ground crew were entering course correction and thruster data using Imperial measures”

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