On the kilobyte, the kibibyte and OS X

[kdum8]

Am I correct in thinking that under OS X a kilobyte is 10^3 bytes? (The name kibibyte now referring to 2^10 bytes).

See attached image showing the info tab for a text file I have.

How can the file be 4 KB on disk and yet only 1,042 bytes of information? That seems like quite a discrepancy. Why does the text consume only 1,042 bytes of ascii information and yet take 4KB to store this to disk? What am I missing?

The file is just a plain text file written in TextEdit.

 

[Satori]

I think the default block size on your HDD will be 4 KB.

 

[cube]

The default allocation block size in Mac OS X is 4KiB. Don't make it smaller.

 

[kdum8]

I think the default block size on your HDD will be 4 KB.

The default allocation block size in Mac OS X is 4KiB. Don't make it smaller.

Ahh I see. So the minimum size that any file in OS X can be is 4 KiB (4*2^10 bytes) regardless of how little data it contains?

 

[Satori]

Ahh I see. So the minimum size that any file in OS X can be is 4 KiB (4*2^10 bytes) regardless of how little data it contains?

That's right.

 

[kdum8]

That's right.

Thanks. That cleared up that mystery.

 

[Mitthrawnuruodo]

Ahh I see. So the minimum size that any file in OS X can be is 4 KiB (4*2^10 bytes) regardless of how little data it contains?

Nah, the file is whatever size it is, ie. smaller, but it uses up a full 4KB "spot" on the disk.

 

[old-wiz]

Different file systems use different minimum size file allocations.
I remember on some older systems the minimum was 8kb.