Storage Space Calculation Query

[ybriK]

So this has been going through my head and toying around with me for a couple of years now. I've done lots of research on it but I'm not quite sure if what I've been reading all these years are correct. Let's talk about storage spaces, in human terms 1 GB is 1000 bytes correct? But in Windows OS terms 1 GB is 1024 MB correct? is it because of the way Windows was built and by that I mean it reads data in two numbers, 1 and 0? Please enlighten me on this as I want this already settled. I've somewhat in an article that Linux reads HDD and other storage devices correctly (in human terms) but I don't know that since I've never noticed it when I had Ubuntu installed in my laptop 2 years ago.

 

Also I'm not sure if this also applies to other OS out there eg. Mac OS, Ubuntu.

[Glenwing]

Yes, a Gigabyte is 1000 Megabytes, Windows thinks that it's 1024 Megabytes though (not because it can't do 1000, but because it was programmed that way).

 

If you plug a 500GB hard drive into Windows it will display as 465GB because it is not actually measuring GB, but something else (called GiB, short for Gibibytes, which comes from Giga-binary-bytes, part of a system which uses orders of 1024 rather than 1000 like SI).  However Windows incorrectly displays GB as the unit of measurement even though it's really measuring GiB.  Similar to taking a measurement in meters but saying it's the number of yards.  It's close but not right.

 

Ubuntu will display the drive as 465GiB, doing the same calculation and using the same formula as Windows but citing the correct units, the things it is actually measuring.

 

Mac OS X will display the drive as 500GB, displaying GB as the unit of measurement, and actually measures in GB as well, unlike Windows and Ubuntu which measure GiB.

 

Basically it's a display error in Windows.  You just have to realize Windows actually measures GiB, so if you see a 500GB hard drive you have to do some conversion to get what capacity that will be in Windows.  Unfortunately Windows displays the unit as the same thing hard drives use when it isn't, so there is confusion about why capacity is "missing" when really it's just in a different unit.

[ybriK]

Yes, a Gigabyte is 1000 Megabytes, Windows thinks that it's 1024 Megabytes though (not because it can't do 1000, but because it was programmed that way).

 

If you plug a 500GB hard drive into Windows it will display as 465GB because it is not actually measuring GB, but something else (called GiB, short for Gibibytes, which comes from Giga-binary-bytes, part of a system which uses orders of 1024 rather than 1000 like SI).  However Windows incorrectly displays GB as the unit of measurement even though it's really measuring GiB.  Similar to taking a measurement in meters but saying it's the number of yards.  It's close but not right.

 

Ubuntu will display the drive as 465GiB, doing the same calculation and using the same formula as Windows but citing the correct units, the things it is actually measuring.

 

Mac OS X will display the drive as 500GB, displaying GB as the unit of measurement, and actually measures in GB as well, unlike Windows and Ubuntu which measure GiB.

 

Basically it's a display error in Windows.  You just have to realize Windows actually measures GiB, so if you see a 500GB hard drive you have to do some conversion to get what capacity that will be in Windows.  Unfortunately Windows displays the unit as the same thing hard drives use when it isn't, so there is confusion about why capacity is "missing" when really it's just in a different unit.

I'm going to save this answer for future reference.