Apple’s Snow Leopard OS completely changed how they’re calculating KB, MB and GB! A Kilobyte is no longer 1024 bytes… now it’s 1000 bytes.

Apparently the new way to refer to 1024 bytes is a KiB, or a Kibobyte. (Which sounds like dogfood to me.) Correspondingly there are MiB, GiB and TiB. Apparently hard drive manufacturers have long used these definitions, but AFAIK, Apple is the first OS to adopt them.

“Apple claims that you can free up to 7GB of hard drive space by upgrading to Snow Leopard (presumably by removing all that legacy PPC code). 7GB ( 1000 ^ 3 * 7 = 7,000,000,000 bytes) in Snow Leopard is significantly less than it was in Leopard ( 2 ^ 30 * 7 = 7,526,192,768 bytes) . So, if Apple hadn’t changed it’s conversion scheme, they could have only claimed that Snow Leopard in fact freed up ( 7,000,000,000 / 2 ^ 30 ) 6.52GB.” via Mac Fanatic.net

To which my co-worker Matt replied:

I think the implication here is incorrect and overly sensational: I can’t imagine Apple switched from KiB to KB solely to make the 7GB marketing claim; 6GB is plenty of reclaimed space!

I blame the stubborn hard drive manufacturers. They’ve won.

This also irritates me:

– viewed using `ls’ in terminal, test1.txt, a 100 MiB file, shows as “100M” using -h:

matt@localhost [511]> ls -l test{1,2}.txt
-rw-rw-r-- 1 matt staff 104857600 Oct 23 08:52 test1.txt
-rw-rw-r-- 1 matt staff 100000000 Oct 23 08:52 test2.txt

matt@localhost [512]> ls -lh test{1,2}.txt
-rw-rw-r-- 1 matt staff 100M Oct 23 08:52 test1.txt
-rw-rw-r-- 1 matt staff 95M Oct 23 08:52 test2.txt

However, using “Get Info” or in the Finder, test1 is 104.9 MB and test2.txt is 100.0 MB.

In…inconsistency in my OS! Aaaaauuugh!

I first read about this at the end of October in MacWorld (though I read the paper copy), and immediately went to Google for confirmation.

It seems incredible to me that this didn’t make a bigger headline splash. Sure enough, my 180 GB Macbook Pro now shows “Capacity: 199.71 GB”.