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View Full Version : Is 100gig Actually 100gig?



skibunny
19th April 2005, 07:05 PM
I just got my first pb and am rapt! I ordered it with the upgrade to 100gig hard drive but looking at the specs in the system profile it only shows up as 93 gig..... :blink:

Does anyone else have this problem? I know at the end of the day who really cares about 7 gig but I feel jipped. :unsure:

the_OM
19th April 2005, 07:09 PM
93gb is the formatted capacity.
for example, there are 1024kb in a megabyte, but they just round it to 1000 for simplicity.

hawker
19th April 2005, 07:13 PM
Yes, it is a 100GB ;)

You're one of them... 1+1 doesn't always equal 2!

feeze
19th April 2005, 07:17 PM
You find that your hard drives actual capacity is 100 billion bytes. But 100 billion bytes does not equal 100 gigabytes. It's due to the fact that computers use binary numbers (base 2), whereas humans use decimal numbers (base 10). Like the-om said, it is rounded for simplicity so humans don't have to bother learning a new number system.

eni
19th April 2005, 07:17 PM
In my opinion, the way hard disks are marketed is atrocious. In my opinion we all are "jipped."

Don't blame apple skibunny, every company that sells hard disks do this. That means all PC computer manufacturers, hard disk mp3 players, etc. Blame the industry.

feeze
19th April 2005, 07:24 PM
Originally posted by eni@Apr 19 2005, 07:17 PM
In my opinion, the way hard disks are marketed is atrocious. In my opinion we all are "jipped."

Don't blame apple skibunny, every company that sells hard disks do this. That means all PC computer manufacturers, hard disk mp3 players, etc. Blame the industry.
I wouldn't necessary blame the industry as much as I would blame human comprehension of maths.

When most people think of the word mega, they think of 1 million which is 1 thousand thousand, and therefore assume that a megabyte is 1000 kilobytes. But in reality 1 mb is 1024 kb. You try explaing that to the average Joe. It would be very difficult from a marketing perspective.

edit: Also you must remember when they made the decision to fudge the numbers, hard drives weren't that big so the gap wasn't that noticiable.

edit 2: spelling and incorrect numbers

skibunny
19th April 2005, 07:38 PM
Originally posted by hawker@Apr 19 2005, 07:13 PM
Yes, it is a 100GB ;)

You're one of them... 1+1 doesn't always equal 2!
Sorry, I'm an accountant, 1 + 1 should always equal 2...if it doesn't, make it! ;)

Anyways, though I'm still confused, thanks all for the reassurance and I'll just accept it that it is 100g.

eni
19th April 2005, 07:49 PM
Originally posted by feeze@Apr 19 2005, 07:24 PM
Also you must remember when they made the decision to fudge the numbers, hard drives weren't that big so the gap wasn't that noticiable.
Good point and I agree.

I don't know who come up with fudging the numbers but I'm sure it wasn't a technical guy. Or at least not one with any real integrity. Reeks of marketing to me.. Does anybody know?

You know what? I can't wait until 1 Terabyte drives start making it into the Dells for the "average joe" and the backlash "WHERE'S MY MISSING 92GBs???!!!" starts (quick mental math is probably completely off, haven't slept in a couple of days).

designers_hub
19th April 2005, 07:49 PM
yep thats how it is in the computer industry.

some thing about the difference between 1024 and 1000bytes.

i must say that apple formatted drives waste more space than window formatted drives. any clues?

kit
19th April 2005, 07:53 PM
feeze - the way humans think about kilo, mega, giga, etc is spot-on. It's computers that have it wrong.

Kilo MEANS 1,000
Mega MEANS 1,000,000
Giga MEANS 1,000,000,000
Tera MEANS 1,000,000,000,000
Peta MEANS 1,000,000,000,000,000

It's just that file systems like to call 1024 a Kilo of bytes. So therefore the established meaning of a kilobyte is 1024 bytes.

So it IS Apple's fault. And Microsoft's and SUN's and everyone else who makes operating systems which incorporate under incorrect numerics.

Of course it's all established now, so it's too late to fix things.

feeze
19th April 2005, 08:06 PM
Kit, you are right. Now that I read over my post I realise that I worded it very poorly. kilo does mean 1000, etc.

It's really a case that it was implemented very poorly within the computing industry. They really should have used a different set of prefixes, but that would probally lead to more confusion.

I think I might just stop arguing though, as I can't even make sense of it, it's all one big fsck up :)

dev_enter
19th April 2005, 08:18 PM
It's not implemented "poorly" in the computing (software) industry. It is implemented efficiently.

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

Hopefully soon we'll all be using the Ki, Mi, Gi, Ti, Pi and Ei symbols.

Phillip
19th April 2005, 08:27 PM
8 Bit = 1 Byte

1 024 Bytes = 1 kilo byte (One Thousand bytes) (or, 1024^1)
1 048 576 Bytes = 1 Megabyte (One Million bytes) (or, 1024^2)
1 073 741 824 Bytes = 1 Gigabyte (One Billion bytes) (or, 1024^3)
1 099 511 627 776 Bytes = 1 Terabyte (One Trillion bytes) (or, 1024^3)

Hard Drive makers use the system of 1,000 Bytes equals One Kilobyte and you computer reads it as 1024 bytes in a kilobyte. Therefore, you hard drive maker might say, 100 GB = 100,000,000,000 bytes while your computer will read 100 GB as only 931,322,574,615 Bytes or 93.132 GigaBytes.

designers_hub
19th April 2005, 08:57 PM
no the computer industry uses 1024 because remember each letter is made up of 8bits.

1000 cannot be divided by 8. You cannot make a computer that runs on Metric units (i.e. 1000 etc). They run on 8, 16, 32, 64, 128, 256, 512, 1024 etc.

geektechnu
19th April 2005, 09:21 PM
designers_hub: no. each ascii character is 8-bits because they are stored in binary. 8-bits of data gives us room for 256 different characters (2^8). 1024 is simply 2^10.

I recall back in the old days, 1.44MB floppy disks would format to around 1.38MB (PC).
If you do the math, it really should format to around 1.40MB - that, my friends is being ripped-off.
Still, nobody complained about it back then. :lol:

Danamania
19th April 2005, 09:47 PM
Originally posted by designers_hub@Apr 19 2005, 08:57 PM
no the computer industry uses 1024 because remember each letter is made up of 8bits.

1000 cannot be divided by 8. You cannot make a computer that runs on Metric units (i.e. 1000 etc). They run on 8, 16, 32, 64, 128, 256, 512, 1024 etc.
This is where the confusion appears. People tend to see the "kilo = 1024" and apply it to EVERYTHING in computing, when it doesn't work that way.

Computers don't TOTALLY run on 8/16/32 (or base 2) type boundaries in arithmetic - only certain PARTS of a computer do, such as cpu registers & addressable memory size (RAM/VRAM, or bus width).

Network bandwidth as one example DOESN'T work this way. It's not dependent on binary addressability but on the speed of a clock crystal. 1 megabit per second is one million bits per second which is 1,000,000 bits per second. One Megahertz is 1,000,000 hertz. One Gigahertz is 1,000,000,000 hertz. Bus bandwidth, memory bandwidth, data on a hard drive platter, baud rate, etc are all measured in base 10 units because they're not necessarily restricted by an addressable data size - unlike a CPU register say... or RAM sizes. While data on a hard drive platter is measured in base 10 - because it could be any mix of blocks/sectors/cylinders, the maximum addressable data across the bus the drive is attached to is measured in base 2. If you have only 32 address bits for that bus, you're only going to be able to address 2^32 locations - so base 2 it is.

Because there's no obvious boundary between what should be measured in base 2 and what should be measured in base 10 just by looking at the names of what's being described (at least to most computer users) the world mixes them all up together, breaks its own rules, and we get silliness like floppies that are measured in base 2 multiples of a base 10 unit (1024 x 1000 = one megabyte on a 1.44 floppy). Why? because the whole kilo=1024 and kilo=1000 have been traditionally used at the same time in the same field which just screws things up. We have a ten megabyte file being transferred across a ten megabit network link and placed in ten megabytes of RAM, and in that process multiple meanings to 'mega' are implied.

Imagine if building a house involved some places where 1 metre is 100cm, and other places where 1 metre is 106cm. Both units are called "1 metre" but they had different sizes. It would be pretty screwed up hey. That's how screwed up computing is without using KiB and KB as two entirely separate units.

Kildare
20th April 2005, 09:22 AM
Regardless of anything the whole HDD size thing is a bit of a scam.
Some of my early HDD's (>2.5GB) actually follow the 1024 sizing - obviously some space is still lost when formatting.

There is no reason why they couldn't contiune to meet the "true" size but obviously it works out cheaper & is better marketing from the current prespective. I don't think comprendable mathematics has anything to do with it.

Many ISPs count 1MB as 1000 bytes so on limited plans your obviously missing out overall.

kim jong il
20th April 2005, 11:08 AM
We had an identical thread (http://forums.appletalk.com.au/index.php?showtopic=6220&hl=) less than two weeks ago discussing exactly the same thing.

kim