The problem is that the manufactures do not tell you how many GIGABYTES the harddisk is able to store. Instead they tell you how many 1.000.000.000 BYTES it is able to store. They do this because it looks better if they can say: "Hey, this is a great 160 GB harddisk!" - but that´s 148 GIGABYTES only. They know that nobody thinks in 1.000.000.000 bytes but in gigabytes. After buying that harddisk you may probably be surprised not to get 160 gigabytes of space; you´ve been manipulated a bit, unfortunately. :-(
Other way around. A gigabyte is 1,000,000,000 bytes. For some reason computer dudes way back when decided to use SI nomenclature for non-SI numbers. 1024 bytes is NOT a kilobyte, 1000 bytes is a kilobyte.
1024 bytes is a binary measurement that is close to a kilobyte but isn't.
When manufacturers say 160GB they mean it. You're buying at least 160 ,000,000,000 bytes. Only problem is when you put that in a computer, the machine, coming from a starting point of being told that 1024 bytes is a "kilobyte" makes the calculations from there and it appears that you've lost about 7% of your starting space even though you've got the same amount of space that you paid for.
The manufacturers are not at fault.
Well, 1000 bytes are "one kilo of bytes", but that is not a "kilobyte"! 1024 bytes are one "kilobyte" (kilobyte is a fixed size you can not adapt to your personal imagines). You could also say 1234 bytes are a kilobyte if you think that´s funny, but the only way your computer works is with 1024 bytes as a kilobyte!
No, there is no grey or context-dependant area of SI prefixes. Kilo means one thousand, no more, no less.
1024 bytes is not a kilobyte. The term kilobyte is the accepted way of saying 1024 bytes but it is erroneous.
This is the definition recommended by the International System of Units (SI) and the International Electrotechnical Commission IEC. This definition is used in networking contexts and most storage media, particularly hard drives, Flash-based storage, and DVDs, and is also consistent with the other uses of the SI prefix in computing, such as CPU clock speeds or measures of performance.
This definition is most commonly used in reference to computer memory, but most software that display file size or drive capacity, including file managers also use this definition.
Why not telling a car-manufacturer that 1 hp is the power of one real horse? If you have a car with 100 hp it should give you the power of 100 real horses! But if you think your car isn´t able to give you the power of 100 real horses, then you should be able to realize that 1 hp is probably something different than YOU think. =P