Ever purchase a 1TB hard drive and find yourself disappointed when it showed up under ‘My Computer’ as 931GiB? If so, you may not have really understood why and felt cheated by the manufacturer. However, there is a simple and innocent reason for this. Computers evaluate numbers on a different base than humans.
As human beings, we generally perceive numbers and mathematics on a 10-base number system. Why? The simplest answer is probably that we have 10 fingers and toes. Thus, 10 is a number which is easy for us to make sense of. This is not the case with computers. Most people are aware that computers perceive data in binary form, or 2-base numbering. There’s always only 2 possibilities. A circuit is either on or off.
How does this relate to the hard drive?
When a manufacturer places memory on the magnetic disks of your hard drive, it does so using SI or metric unit values which increment by the 1000s (1GB = 1000MB = 1000000KB…). As such, with the earlier 1TB, you’re really purchasing 1(1000^4) bytes of data.
Now, when a computer goes to measure this disk space it does so differently. You still have 1(1000^4) bytes. However, the conversion between units is different. Unit values are instead converted as powers of 1024 instead of 1000. The reason? 1024 is the power of 2 that was chosen at some point. Perhaps because it’s 2^10 and someone thought that would be easier for humans to make sense of (I can only speculate). This means that 1TB to a computer, is really 1024GB
To make up for this confusion, the IEC standardized a unit system for computer memory which uses units such as the Kibibyte in place of the kilobyte. Hopefully this system will take over and alleviate the confusion from earlier.
But why did I decided to write an article on 10-base and 2-base number systems? The simplest answer would be that I was bored out of my mind but I also wanted to provide a good preface of information for using a little java applet I wrote for fun (I’m odd and code for fun) that converts these units for a user. You’ll find it on the Memory Unit Converter page of this website. I have a statistics application which I’ll be posting soon too.