Trying to convert value into GB

Getting Started
1

Hi i am using MBS Util plugin to return a drive size

format(f.VolumeSizeMBS/1024.0/1024.0/1024.0,"0.0")+" GBytes"

My HDD size is 652GB, but the above only returns: 607GB

Is there a way to calculate drive size and free space native in XOJO or can some please help with the above MBS issue?

Thanks

2

is that on Mac OS X?

3

for Mac OS X in newer versions you use /1000 not /1024.

4

Depends on how you define a Gigabyte [base 10 or base 2]

normally it is 1,073,741,824 bytes, not 1,000,000,000 (which is a billion bytes)

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

5

for storage, ENGINEERING sizes are /1024. for MARKETING/SALES sizes it is /1000

plus the Volume size might not show the FULL disk as you have to partition the drive and create a filesystem that take overhead. Not sure if that is taken into account.

sb

6

Linux, most probably.

7

Ought VolumeSizeMBS to return the size of the HDD or of the partition? I guess that is where the difference could come from.

8

It’s also related to the advertised capacity versus the actual, usable capacity. For example, a 250GB drive has 238GB usable. A 2TB disk has 1.83TB usable.

I suspect that what you’re seeing, Jay, is actually correct.

9

Well, Tim, advertised is calculated with /1000, but usable was for long calculated with /1024.
Nowadays Apple divides usable also with /1000, so the numbers advertised and shown in Finder match.