09-03-2007, 07:41 AM

I have just got my new black macbook.

It is ment to be 160gb hdd but when i go on "get info" on the hard drive it says that the capacity is 148.73. Shouldent this be 160?

09-03-2007, 07:49 AM

Thats Normal. How it works is it will round it off to the nearest gb.

If you look at the mb it should be 160000000mb something like that. I don't know the exact numbers.

Someone else will give you a better answer.

Just google a conversion for Gigabytes and megabyte and you will see what i mean.

09-03-2007, 09:56 AM

Also, I think most manufacturers specify the drive size in thousands of megabytes, rather than actual gigabytes - ironically because they say it's confusing for users... A thousand Megabytes is less than an actual, real Gigabyte.

09-03-2007, 10:13 AM

1GB = 1 billion bytes when advertised.

09-03-2007, 11:01 AM

1gb true conversion is below:

1000mb = 0.9765625gb

09-03-2007, 11:27 AM

It's because, as humans, we work on the decimal system: 1000KB = 1MB, 1000MB = 1GB, 1000GB = 1TB etc. Computers on the other hand work on the binary system: 1024KB = 1MB, 1024MB = 1GB, 1024GB = 1TB etc. This means that when you buy a 160GB drive, it's not truly 160GB; it's missing the extra bytes that a computer needs to count as a full GB which we don't count.

When advertising small capacity media the manufacturers tell you quite clearly that you're buying 32, 64, 128, 256 or 512 megabytes, but then for larger capacity media they round off.

And I may be wrong in this, but I believe different formatting also affects how much of the space is available to the computer.

09-03-2007, 11:38 AM

It's mostly to do with the formatting of the drive. You lose a fair bit due to the formatting process and flags being set and then some to the conversion.

1GB is actually 16,777,216KB (which is what the OS will recognise it as) rather than 16,000,000KB that hard drive manufacturers go by.

My 20GB Xbox 360 hard drive only had 12GB of usable space once formatted and had the OS on it!

09-03-2007, 11:54 AM

What Levi said is correct. My 120GB harddrive is actually 111.35GB once the converstion from decimal to binary is done. Once the OS and included applications were all installed i ended up with a little over 100 GB of space remaining.

09-03-2007, 08:29 PM

ilife takes up a lot of the space on your brand new drive. My 80 GB drive came with about 65 free.

Jason

09-03-2007, 08:43 PM

GarageBand takes up a couple of gig as well. Get rid of some of the stuff you don't want/need.

Monolingual is a program used to remove the extra languages that come with OS X. I got rid of most of them which gave me back around 200-300Mb.

09-03-2007, 08:58 PM

OS Makers - 1Gb = 1024Mb

HDD Makers - 1Gb = 1000Mb

You do the math.

The capacity of an HDD can be calculated by multiplying the number of cylinders by the number of heads by the number of sectors by the number of bytes/sector (most commonly 512). On ATA drives bigger than 8 gigabytes, the values are set to 16383 cylinder, 16 heads, 63 sectors for compatibility with older operating systems. It should be noted that the values for cylinder, head & sector reported by a modern drive are not the actual physical parameters since, amongst other things, with zone bit recording the number of sectors varies by zone.
Hard disk drive manufacturers specify disk capacity using the SI prefixes mega, giga, and tera and their abbreviations M, G and T, respectively. Byte is typically abbreviated B.
Operating systems frequently report capacity using the same abbreviations but with a binary interpretation. For instance, the prefix mega can also mean 220 (1,048,576), which is approximately 1,000,000. Similar usage has been applied to prefixes of greater magnitude. This results in a discrepancy between the disk manufacturer's stated capacity and what the system reports. The difference becomes much more noticeable in the multi-gigabyte range. For example, Microsoft Windows reports disk capacity both in decimal to 12 or more significant digits and with binary prefixes to 3 significant digits. Thus a disk specified by a disk manufacturer as a 30 GB disk might have its capacity reported by Windows 2000 both as "30,065,098,568 bytes" and "28.0 GB" The disk manufacturer used the SI definition of "giga", 109 to arrive at 30 GB; however, because the utilities provided by Windows define a gigabyte as 1,073,741,824 bytes (230 bytes), the operating system reports capacity of the disk drive as 28.0 GB.

Source.

09-04-2007, 09:10 AM

u gotta remember they installed OSX and Ilife08 on it so dont forget that

09-04-2007, 10:20 AM

I don't think he's worried about free disk space, more lack of total disk space vs. actual advertised capacity. iLife has nothing to do with a 160gb drive showing up as only 148gb total drive capacity.

And if any one goes to use monolingual, be very careful and read directions...it can toast you OS X install from everything I've been reading...

09-04-2007, 11:28 PM

You are noticing a couple of issues.

First the drive manufacturers don't measure a megabyte and gigabyte as computer professionals would. So you loose many many bytes to this funny manufacturer math. Arguably fine for consumers until they use a tool that tells them otherwise that was written by a computer professional.

To a computer professional, a megabyte is;
1024*1024*1024 = 1,073,741,824= 1GB.
To the drive manufacturers a megabyte is;
1000*1000*1000 = 1,000,000,000 = 1GB.

So, if I did the math right, you loose 11,798,691,840 (11.7GB) of raw space on the 160GB drive to consumer math. The I.T. pro would expect to get the 11GB.

For my 160GB Seagate drive, Disk Utilitiy has this line;
Total Capacity : 149.1 GB (160,041,885,696 Bytes)
Where is that extra 41,885,696 bytes coming from? The manufacturer was nice enough to give me some bonus bytes. By the way, Get Info gives me the same answer you have. Perhaps that is part of issue two...

Second when a drive is formatted, an amount of the total is used in the formatting structure. This is too difficult to explain, perhaps wikipedia has a fair explanation. Basically some bits are used up as markers between blocks of user data. Also some bits are used for error checking.

Anyway, you have what you paid for, like it or not. The math is explained somewhere on the box for the drive, when you buy them.

09-05-2007, 12:23 AM

Originally Posted by Village Idiot

I don't think he's worried about free disk space, more lack of total disk space vs. actual advertised capacity. iLife has nothing to do with a 160gb drive showing up as only 148gb total drive capacity.

And if any one goes to use monolingual, be very careful and read directions...it can toast you OS X install from everything I've been reading...

I haven't experienced any problems since using it...