Say you just bought your brand new (external/internal) hard disk drive, and you’re keen to use the additional hard disk space to store video, photo or any other data. However, after you check out the available disk space of your still empty hard disk drive, the amount of GB available is substantially less than is advertised on the box. You might think there is something wrong, but in truth there isn’t.
The hard disk drive manufacturers advertise a gigabyte as something dissimilar than what your operating system (e.g. Windows) recognizes. Computers use a binary system, which means if you put it simple that everything is “2 to the power of X”: 2,4,8,16,32,64,128,256,512, 1024, etc. Maybe you notice that some these numbers are also found in many computer related devices: for example, your (old) computer may have 512 MB of RAM, or your MP3 player has 1024 MB, which is 1GB of flash memory.
This is exactly where it goes wrong with our hard drive example. The manufacturers all advertise with drives in (currently) Gigabyte (GB) or Terabyte (TB). However, they use the decimal meaning of the words “Giga”, so a hard disk drive of 1 Gigabyte contains 1000 Megabytes according to the manufacturers, while Windows would say: no, 1024 Megabytes is one Gigabyte. Same holds true for the difference between other ‘levels’, so the difference each time is 2.4% - see the table below.
As you can see from the example, this means that if you have a drive that says on the box 500GB, you’ll have a maximum of about 464 GB disk space available in Windows.
It has been discussed that steps should be taken to prevent customers for being misinformed, but so far all that has happened is that most manufacturers display a small warning on the box. Best thing we advice is to think of this article when shopping for hard disk drives: this ensures you are not taken by surprise and that you are informed and know what you will be buying.
