how big is my hard drive?

Hi, I got my new iMac 1 week ago and love it! I am just finishing switching over my files from the old pc to the new machine.

My question is about my hard drive and it's size. I have the 20", model #MB324LL/A which the box says it is a 320gig hard drive. When I click on my hard drive on the desktop it says I have 234.08 gigs of space available. in all the files i have transfer over I know that it has not been more than about 20 gigs. where are the missing gigs?

below is a "cut and paste" of the machines hard drive specs which says 297 gigs???
Intel ICH8-M AHCI:

Vendor: Intel
Product: ICH8-M AHCI
Speed: 3.0 Gigabit
Description: AHCI Version 1.10 Supported

Hitachi HDP725032GLA380:

Capacity: 298.09 GB
Model: Hitachi HDP725032GLA380
Revision: GM0KA59A
Serial Number: GEK033RG1K1E8C
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Mac OS 9 Drivers: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
Macintosh HD:
Capacity: 297.77 GB
Available: 234.08 GB
Writable: Yes
File System: Journaled HFS+
BSD Name: disk0s2
Mount Point: /

That seams about right...

The advertised drive size is without it being formatted...
The actual formatted capacity of drives can be around 10-15 gigs smaller than the advertised size.

I have a 500 gig SATA drive that only has 465 gigs after being formatted. So you number sound right. Try running WhatSize to get a real clear picture of what is on your drive.
http://www.versiontracker.com/dyn/moreinfo/macosx/21149

Disk Inventory X does the same thing but I prefer it.

http://www.derlien.com/

Garblefarb!

This "lost to formatting" stuff sounds like the kind of garblefarb you get from the untrained high school kids working as "Sales Consultants" at Best Buy.

The truth is that your hard drive can indeed hold 320 gigabytes of data. To be precise, that's 320,000,000,000 bytes.

Us humans use the decimal system to represent numbers, wherein we express numbers as powers of 10. So we normally refer to amounts of data in “chunks” of thousands (kilo), millions (mega), billions (giga), etc.:

1,000 bytes = 10^3 bytes = 1 kilobyte
1,000,000 bytes = 10^6 bytes = 1 megabyte
1,000,000,000 bytes = 10^9 bytes = 1 gigabyte.

Since computers were designed around very basic electrical “switches” which can either be “on” or “off,” it was natural for them to use the binary system (where “off” represents a “0,” and “on” represents “1”) to process data. Now, as it turns out, two to the tenth power, 2^10, is 1,024, which is very close in value to 1,000 (10^3). Similarly, 2^20 is 1,048,576, which is approximately 1,000,000 (10^6), and 2^30 is 1,073,741,824, which is close to 1,000,000,000 (10^9). Consequently, the computer folks (being human ) began applying the abbreviations normally associated with decimal numbers to binary numbers. This led to 2^10 being given the prefix “kilo,” 2^20 given the prefix “mega,” and 2^30 being referred to as “giga.” So, in the Wonderful World of Computers,

1,048,576 bytes = 2^10 bytes = 1 (binary) kilobyte
1,048,576 bytes = 2^20 bytes = 1 (binary) megabyte
1,073,741,824 bytes = 2^30 bytes = 1 (binary) gigabyte.

The bottom line is this: The capacity of your hard drive can be expressed in either notation. Since 298 binary gigabytes is the same as 320 decimal gigabytes, what do you think the marketing folks want to have printed on the outside of the box? ;D

You can understand why we (and Apple) say "Actual formatted capacity less." rather than that, though.

Mark W said:

You can understand why we (and Apple) say "Actual formatted capacity less." rather than that, though.

Click to expand...

Not entirely. Being told that the actual formatted capacity is less than the stated capacity is a "FYI" statement that would hold regardless of what measure was used to advertise the drive's size. In and of itself, such a statement is not at all confusing. But when a system profile—which (AFAIK) reflects the drive's total size—shows that your drive is 7% smaller than the stated capacity, that's very confusing. (Were it not so confusing, we wouldn't be having this discussion, would we? )