[X4U] External HD: 750 gig to 699 when formatted. Why???

[Chris Jones]

> I bought a SimpleTech 750gig external HD. It was Windows formatted  
> in the first place. Once mounted, info window showed the drive had  
> 699 gig free. As suggested in the instruction manual (and as should  
> be done) anyway), I reformated the drive Mac OS Extended journaled.  
> Still 699 gig free. Is there a way te recover this huge amount of  
> lost gig? What are they used for and by what (whom)? Are there some  
> hidden Windows programs and files left on the HD. If so, how to et  
> rid of them to recover that space?

Don't worry, this is a trick used by disk makers to make their disks  
seem larger than they are. Basically, they use a difference definition  
of 'GB' to what your system is using.

They use a system where '1 gigabyte' = 1000000000 bytes, whereas your  
system uses '1 gigabyte' = 1073741824.

If you want more details, see for instance

http://en.wikipedia.org/wiki/Gigabyte

The confusion comes from the fact the term 'GB' tends to used for both  
definitions. The correct thing to do is to use 'GiB' for the system  
used by the hard disk makers. So your disk is actually 750 GiB or in  
other units, 699 GB. If you do the maths you will see  
(1073741824/1000000000)*699 = 750

So don't worry. You haven't lost any disk space, its just not quite as  
big as you thought...

Chris
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