Question about disk space

ghall

macrumors 68040
Original poster
Jun 27, 2006
3,773
1
Rhode Island
Okay, this is something I have been wondering for a while now, so I just thought I'd ask. I have an 80 GB hard drive on my MacBook Pro, but the Macintosh HD has only 74.21 GB. Where is the other 5.9 GB? I know it has something to do with formatting, but I'm not entirly sure why this happens.
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
17,230
1,124
It has to do with the difference between gigabytes and gibibytes...computers and hard drive manufacturers see things differently. This question gets asked here a lot, so I'll direct you to another thread that answers the question a bit more thoroughly.
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
17,230
1,124
It comes from the fact that 1 kB is equal to 1024 bytes...that's how your computer sees it. But hard drive manufacturers like to use base-10 systems, so they call 1 kB equal to 1000 bytes. So there's a 2.4% difference in capacity at the kilobyte level. But this error compounds itself as you continue to go up through prefixes...by the time you get to gigabytes, it's a pretty noticeable amount. It will only get worse as capacities continue to increase.