Question for the Computer Gods.

[bigjimaz]

It's not a problem but I have a question about my hard drive.

When I bought the computer it said I had an 80 gig HD. It's one of those el-cheapo Dell 2300 that they were selling back in late 2005 for $300. Anyway, when I defrag it lists my HD capacity at 71.04 gigs. Where did the other 8.96 gigs go? It's not like it matters. I'm only using 29% of it anyway and it's been saying this since I bought it I'm just curious. Understand please that my knowledge of computers is capable of being stored in a small thimble.

TIA and try not to laugh too hard at my obvious lack of knowing much more than my computer is black and gray.

[Broomjockey]

Most of the time they do 1Gig = 1,000,000,000 bytes, or however many zeros they put, rather than the accurate 1 gigabyte = 1 073 741 824 bytes, but your computer calculates it properly, meaning it shows less. Also, the OS takes up space that isn't considered most times, and the file allocation table can take up unaccounted space as well.

[lordlundar]

Most of the time they do 1Gig = 1,000,000,000 bytes, or however many zeros they put, rather than the accurate 1 gigabyte = 1 073 741 824 bytes, but your computer calculates it properly, meaning it shows less. Also, the OS takes up space that isn't considered most times, and the file allocation table can take up unaccounted space as well.

That's pretty much it. The bulk of the missing space is due to the manufacture and advertising is done on a base 10 setup (ie 10 to the n power giving 1, 10, 100, etc.) while a computer uses a base 2 setup (2 to the n power giving 1, 2, 4, 8, 16, etc.)

As well, the File allocation table, which is used to find the stuff on the hard drive is created on formatting the hard drive and is inaccessible by the OS, so that simply gets ignored or is on an invisible partition. The OS also does something similar which takes up a small chunk of it as well.

You have no idea how many times I get asked this question. It's hit the point where I can fire it off automatically. Then I get pissed when people tell me I'm wrong.

[Seshat]

If you don't ask, you never find out.

Broomjockey and lordlundar are right. It's a combination of the different base, and the formatting.

As an analogy, your house might occupy fifty square metres (or yards, if you prefer) of ground. Of those fifty square metres, however, you can only use 49. The remaining square metre is taken up by the space the walls occupy.

Except in this case, the 'walls' are a few things the operating system uses to keep track of things. If we try to extend the analogy, it kind of falls flat on its face, so we'll leave it at that.

[sms001]

80 gig HD. <snip> 71.04 gigs. Where did the other 8.96 gigs go?

When I first read your post I thought that almost nine gigs was a little high for overhead and thought there might be a recovery partition involved (a hidden area of your disk that Dell can use to restore your machine to its "out-of-the-box" state) but probably not:

1MB= 1,048,576 B vs. 10^ 6 means a 4.6% difference
1GB= 1,073,741,824 B vs. 10^ 9 means a 7.0% difference
1TB= 1,099,511,627,776 B vs. 10^12 means a 9.0% difference
1PB=112,589,990,6842,624 B vs. 10^13 means a 11.2% difference

So 80 - 5.6 GB for math differences right off the bat leaves 3.36 GB unaccounted for which I can easily believe to be formatting, bad sectors, file allocation overhead etc. I hadn't really realized that there is a curve function involved in the whole kilo = 1000 VS. kilo = 1024 debate before, so thanks bigjimaz - I learned something new.

(BTW, this math nomenclature thing has been a Looooooonnnnggggg running argument amongst geeks. It's pretty silly. As long as all the hard drive manufacturers do the same thing, I could care less.)

[Broomjockey]

The funny thing is I made my techie friend scream with that thing. I hooked up my new "320" gig HDD, and asked "Where's the rest of my space?"

He almost had an aneurysm.

[Naaman]

(BTW, this math nomenclature thing has been a Looooooonnnnggggg running argument amongst geeks. It's pretty silly. As long as all the hard drive manufacturers do the same thing, I could care less.)

That's not the issues - the drive manufacturers have always done their thing and the OS's have have done a different thing. Technically the drive manufacturers are wrong, although it looks like things may be sorted out soon: Seagate lawsuit

[sms001]

That's not the issues

huh? What's not an issue?

- the drive manufacturers have always done their thing and the OS's have have done a different thing.

Yep. Decimal. Binary.

Technically the drive manufacturers are wrong, although it looks like things may be sorted out soon:

I won't get into the whole right/wrong thing, it's irrelevant. The thing is, (to look more impressive than they were, honestly) every hard drive manufacturer I've ever run across has used decimal nomenclature to describe their product. That makes it a de facto standard. If I buy a Western digital 80GB and format it NTFS and I buy a Seagate 80GB and do the same, I get the same amount of usable space because they started with the same raw capacity. That means I'm comparing apples and apples. Now if EVERYONE used Binary except Western Digital, I could see the sense in crying deception. Their HDs would falsely appear larger at the same price points. But they don't. They shouldn't have been found guilty last year, and Seagate shouldn't this year. It's sucky customers and illogical courts.

[Pedersen]

If I buy a Western digital 80GB and format it NTFS and I buy a Seagate 80GB and do the same, I get the same amount of usable space because they started with the same raw capacity. That means I'm comparing apples and apples. Now if EVERYONE used Binary except Western Digital, I could see the sense in crying deception. Their HDs would falsely appear larger at the same price points. But they don't. They shouldn't have been found guilty last year, and Seagate shouldn't this year. It's sucky customers and illogical courts.

Gotta chime in here. Here's why it's an issue:

How much memory do you get when you buy one gigabyte of RAM? 1,073,741,824 bytes. How much memory do you get when you buy two gigabytes of RAM? 2,147,483,648 bytes.

When you ask the operating system the size of your disk (not the size of the partitions, but the actual size of the disk), what number does it use to calculate the number of bytes per gigabyte? 1,073,741,824 bytes. This is true under Windows, Linux, and Mac OS X.

So, for all things in the computer, your computer looks at a gigabyte as having 1,073,741,824 bytes. Along comes the hard drive manufacturers, who have decided to sell their disks using the 1,000,000,000 bytes per gigabyte definition. End result? Two disparate definitions. You wind up with a drive that you bought thinking it was a 320GB hard drive, when it's really 298GB by every other definition in use in the computer.

Look at that number. There's 22GB of difference. You could store over half of a Blu-Ray disk there. That's (at 5MB per song) ... At least 4000 more songs (that allows for major rounding error). 5 full DVD ISO images for Linux distributions. The list goes on and on.

That's a lot of space. And it's space that, if the hard drive manufactures followed the already existing de facto standard used by the rest of the computer, you would have and be able to use. By using a number that's out of sync, they get to claim bigger capacity. They're duping you.

[lordlundar]

The reasoning behind it believe it or not, is profits. Memory used to be very expensive, and hard drives were expanding at a rapid rate, often times so much that manufacturers couldn't keep up. So manufacturers decided to play to this and manufacture their products in a base-10 setup to save money. It hasn't changed in all this time because not enough people smart enough to figure it out. RAM on the other hand always has been much smaller so adding a couple more bytes never really made much difference.

I know, it's stupid and it sucks. But no one who said life is fair is alive now.

[JustADude]

By using a number that's out of sync, they get to claim bigger capacity. They're duping you.

I'll second that. And because so many people fall for it, It's going to take some major litigation to get them to change their standards, and those law-suits are what will do the job if people keep them up. It's about time.

[Broomjockey]

I'm all for them changing it just to make it no longer an issue, sod whys and wherefors. Gimme some freaking standardization! There's enough incompatabilities in computers without arbitrary ones.

Of course, once we get the HDD people to fall in line, there's the mp3 player manufacturers et al. to go after.

[rvdammit]

Just a little Devil's Advocate here but the drive manufactures are using giga in a technically accurate way. It is the SI prefix for decimal multiples, specifically 10^9, the corresponding SI prefix gibi is for binary "equivelent", 2^30, abbrreviation Gi.

[JustADude]

Just a little Devil's Advocate here but the drive manufactures are using giga in a technically accurate way.

Yes, but remember that when something is "technically" ANYTHING, that just means that someone found a loophole and scammed their way in. This goes for any situation.

[ahanix1989]

A quick rule of thumb, for most operating systems and filesystems, 7% of the raw capacity will be non-user storage.


For example, my current system. A single 400GB hard drive. The 7% rule would tell me that I should have 372GB of available capacity. I have three partitions, 68.3, 284, and 19.5GB. Add those up, I get 371.8GB, and Windows is probably rounding off the 284.

So.. use that as a support. If you can confidently say "7% is used for the table of contents" and show them that they are missing 7%, it should work.