Why it's not 80GB?

[chrisling]

I feel very strange on my Seagate ATA HDD 80GB. I realize it has only 76++GB, it shows so when I did my reformatting last night in the Windows setup. I did checked the BIOS update patch for my motherboard, that's Asrock 775VM800, but I can't get the update for detecting larger hard disk. They're only for VGA updates and some other stuff that's not relevant with HDD. Usually I'll check my hard disk whether with Command Prompt or by software (Seagate HDD utilities and SpinRite), but found no bad sectors.
I really appreciate every help you guys offer...

[pave_spectre]

The hard drive manufacturers use multiples of 1000 to specify the size of drives, but the computer uses multiples of 1024 to determine hard drive size.

So the hard drive is 80,000,000,000 bytes large, which when divided by 1024 several times, becomes 76 GB (or more correctly 76 GiB)

[chrisling]

So that's mean for more appropriately, my HDD is actually 76GB but not 80GB?

[Pentium100]

It is both, depending on what you call 1GB. If it is 1'000'000'000 bytes then your HDD is 80GB (that's what manufacturers use) if it is 1'073'741'824 bytes then your HDD is 75GB (that's what Windows use).

It's sort of measuring temperature in degrees Celsius and degrees Fahrenheit (for example, my room's temperature is either 35 degrees or 95 degrees depending on which "degree" is used)

[chrisling]

That's mean each company has their own measurement on HDD size doesn't it? Just like the temperature, celcius and Ferenheit, both are temperature measurement but in different unit... :p

[azzey]

Microsoft is doing it the right way. Since the beginning of time, a GB has had 1024MB. It was only when the hard drive manufarturers started getting greedy, and found a way to make it seem like the drive was bigger, has this problem affected anyone. It is quite annoying.

[chrisling]

Yup it's annoying so I wrote this post :p But what in my mind is Giga=1000Mega, hardly to make it to 1024 Mega...For me, Micorsoft did the confusing information... :p

[azzey]

Hehe... Microsoft did the logical thing and followed the system that has been in use since the first computers! I will agree with you in that Mega usually means 1000--normally this is the case. Megahertz is an example. One megahertz is 1000 Hz, not 1024 Hz.

Magic numbers when it comes to computers--1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048 and so. Can't argue with that!

It's also confusing because you never know what the measurement is--if you read '100mb' you have no idea whether it's 100 true megabytes, or whether they're counting 1000 bytes as a megabyte. Darn confusing, and even more confusing to a novice user!

[jlreich]

Well with an 80GB HDD is not that big a deal. But get into hundreds of GB's and the difference gets to be pretty big.

For instance my 250GB HDD's are actually only 233GiB. So out of 500GB of HDD space I only actually have 466GiB. Just a matter of what type of math is used.

Western Digital just settled a class action suit that had to do with this very issue. :rolleyes:

Edit -

It's also confusing because you never know what the measurement is--if you read '100mb' you have no idea whether it's 100 true megabytes, or whether they're counting 1000 bytes as a megabyte. Darn confusing, and even more confusing to a novice user!
Actually it is getting better as many manufacturers are starting to use the GB, MB etc =1000 bytes, and GiB, MiB etc =1024 bytes naming convention.

[chrisling]

I fell like being cheated when I buy a HDD and it's actually not the exact GB of it :(
But anyway, it Microsoft's wrong, hehe...:p

[jlreich]

You are not really being cheated either way. It's still 80 billion bytes no matter the math that is used. But computers do function in binary, so it would seem logical to report all measurements in binary as well. So some see it as a deception. Which in that way it is a deception to the average consumer since they (HDD manufacturers) do it on purpose.

Here is a good link if you want to know what it really is about. http://en.wikipedia.org/wiki/Gigabyte

[pentachris]

if you read '100mb' you have no idea whether it's 100 true megabytes, or whether they're counting 1000 bytes as a megabyte.

Just to pick a nit, and possibly make things more confusing...

100 mb is not 100 megabytes of any sort. It's 100 megabits of some sort.

b=bits

B=bytes

(8 bits per byte)

:p ;)

[azzey]

I noticed that after but it was too edit it and change it http://www.pcguide.com/ubb/biggrin.gif!
I was hoping no one would notice... http://www.pcguide.com/ubb/redface.gif

[chrisling]

I'm the who didn't notice... :(