The Great Capacity Swindle

[HopperJF]

DBAlex wrote:
Off topic issue but you were ripped off anyway...

I got a 320gb external IOMega drive for about £50 just after christmas...

But yeah, they allways do calculate the capacity wrongly, I thought it was common knowledge.

Only problem I have with the external HD is the speed, backing  up over USB2.0 isn't really realistic... and I haven't found anything nearly as good as Time Machine for XP/Vista.

I know, but it was bought on impulse and out of Maplin and Currys Digital (which are probably the same company anyway) the Currys Digital WD one was cheaper (Maplin wanted £80 for the same capacity but a DRM one)

Sooner or later though, they are going to have to change aren't they, because the gap is getting increasingly bigger everytime, when it goes into hundreds of gigabytes surely its time to change the way the capacity is marketed

[monami]

lcd screen sizes are at least correct as they don't count the tube you don't use.

[tokyoracer]

The XBOX 360 drive is worse, they say 20GB but it's only 13GB. Very silly.

[nBit7]

Not Really a Swindle....  
Heres a explanation from wikipedia.  
"Hard disk drive manufacturers specify disk capacity using the SI prefixes mega-, giga- and tera-, and their abbreviations M, G and T. Byte is typically abbreviated B.

It Is a SWINDLE.

That wikipedia quote is deceptive and should be changed in my opinion.  (And I bet is has been changed many many times)
It implies that Hard drive manufactures have been rightfully using the SI standard since the beginning.  This is not the case, as only since around 2000 has the SI defined the use computer terms kM MB and GB as being 1000 not 1024.
There is a JEDEC standard that pre-dates this by many years that defines the 1024 usage.

All(?) Operating systems that use these storage devices use the 1024 bytes per kB standard.  How is it OK for Harddrive manufactures (or ISPs) to use a different standard.

The SI standards body did us all a big disservice by setting this silly standard.  The different named definitions (kiBi) should have been made to the decimal version not the binary.

[ChuckT]

I'm sure if you read the fine print on any hard drive, they tell you what you are actually getting.  

[pyrre]

All(?) Operating systems that use these storage devices use the 1024 bytes per kB standard.

Yes they do. but when calculating anything above 1KB OS's multiply by 1000 making 1GB 102400Bytes instead of 1047576Bytes.

The SI standards body did us all a big disservice by setting this silly standard. The different named definitions (kiBi) should have been made to the decimal version not the binary.

Well i disagree... the SI standards are made to differ in terms. KB is Kilo Byte and can be interped as 1000 Bytes. In SI standards it is totaly correct. However KiBiByte is Kilo Binary Byte and cannot be interped "the wrong way" it uses the binary number sequence. while KB can be using decimal number. And therefor not entirely correct...

[motorollin]

The best you could hope for by taking this to Trading Standards (or the equivalent depending on which country you live in) would be them forcing the manufacturers to specify that they had used a decimal rather than binary equation to calculate the capacity of the disk. But anybody who knows the difference will already know that hard disks are never formatted to the advertised capacity, and people who don't know the difference will still expect a 160GB drive, even if the packaging says "160GB (decimal)".

--
moto

[nBit7]

Well i disagree... the SI standards are made to differ in terms. KB is Kilo Byte and can be interped as 1000 Bytes. In SI standards it is totaly correct. However KiBiByte is Kilo Binary Byte and cannot be interped "the wrong way" it uses the binary number sequence. while KB can be using decimal number. And therefor not entirely correct...

Well I can't argue that KiB is NOW unambiguous.  However GB, MB, KB and kB are now as a result of SI, almost completely useless as they have set a standard that goes against decades of accepted usage.  The only Computer related system previous to 2000 that didn't use exclusively use 1024 was magnetic media.

It would have been fine if they set two new terms instead of redefining an accepted computer and electronics standard (and a JEDEC standard).  
eg: define KiB and KeB (i=bInary e= dEcial) or similar.  That way there would be no ambiguity when the SI standard was taken up, unlike what we have now with kB.

[bloodline]

I have just bought a 320Gig HD to put inside my MBP... wow... Once formatted it's about 298gig... hello where did my 20gig go!!! Hehehe, I'm not actually bothered since Hard drives for what ever reason have always been measured in decimal bytes by manufacturers. I don't care since they are all sold like that... but what the hell... that's a lot of space inside a laptop!!!  :-)

The problem we face now, is that if we wanted to move the more helpful Binary system, ALL manufacturers would have to do it together. Nothing would be worse or more confusing than manufacturers stating different capacities for the same size drive.

What we might see is a change with SSDs... since these are built using Chips and therefore inherently measured in powers of 2... we might expect to see a shift to binary sizes over decimal ones.

I notice that my old 540Mb HD in my A1200 is about the same size as my 512Mb Compact flash...

[nBit7]

At the end of the day I just hope that OSs don't start using the SI definitions as that would just wast more cycles to display the value.   As a power of 2 divide is only a left shift away.

[nBit7]

Yes they do. but when calculating anything above 1KB OS's multiply by 1000 making 1GB 102400Bytes instead of 1047576Bytes.

Which OSs?

An example from my winXP system:
filename: AmigaTribute.mp4
size: 20.6 MB (21,604,082 bytes)

21,604,082 bytes / 1024
= 21098.7 kBytes

21098 / 1024   (NOT 1000)
= 20.6 MB


I know there are some examples in the computer area where 1024 bytes = kb then 1000 = MB, GB have been done but they are a small minority

It would take an OS many more cycles to calculate the 1024 1000 1000 version vs a 1024 1024 1024 system.

[jorkany]

Yes they do. but when calculating anything above 1KB OS's multiply by 1000 making 1GB 102400Bytes instead of 1047576Bytes.

Wrong.

Well i disagree... the SI standards are made to differ in terms. KB is Kilo Byte and can be interped as 1000 Bytes.

A kilobyte is 1024 bytes, regardless of any effort by marketing boards to redefine it.

[darksun9210]

also...
if you format a drive to have 512byte blocks, you loose part of the 512bytes with header/pointer information. the smaller the block size, the more headers, the more diskspace lost. so a 2Kbyte block formated disk looses one quarter the disk space compaired to a 512byte block formatted disk. sounds great huh? but wait a minute. a file cannot be smaller than one disk block, and a block cannot contain more than one file. so a 512byte file saved to a 2Kbyte block, leads to 1.5Kbytes of empty (slack) space that can't be used by anything else.
also, if you have a few massive blocks, even if you have lost of disk space left, if all the blocks are used up, you won't be able to save anything to the drive.
most the time thats why "file size" and "size on disk" is different. size on disk takes into account all the 'slack' space used by incompletely filled blocks, plus the block headers.
so you have to weigh it all up.
if you have a disk that is going to have a few massive files on it, its best to use a large block size, as you get more disk space back, and the drive has less indexing work to do, meaning its a bit faster, especially in a serial read/write scenario (aka video recording/playback).
if you have lots of tiny files, you really want a small block size so you don't waste disk space with lots of 'slack' space.
i know with todays massive drives, its not so much the concern it once was when we were piddling about with drives in the tens to hundereds of megabytes. but it can make a difference with drive performance, and percieved capacity.
ok so you accept that your nice 1000GB drive is counted in decimal, so you plug it in and accept the 50GB+ loss in actual capcity, but you then loose another what, 9Gb in formating? yay!

sorry for the essay... bored... lol   :lol:

[ZeBeeDee]

Taken from Seagate's FAQ's about their drives ... Western Digital say the same thing ...

Quote ... "Hard drive manufacturers market drives in terms of decimal (base 10) capacity. In decimal notation, one megabyte (MB) is equal to 1,000,000 bytes, and one Gigabyte (GB) is equal to 1,000,000,000 bytes.

Much of this information is available from the National Institute of Standards and Technology at http://physics.nist.gov/cuu/Units/binary.html

Programs such as FDISK, system BIOS, and Windows use the binary (base 2) numbering system. In the binary numbering system, one megabyte is equal to 1,048,576 bytes, and one gigabyte is equal to 1,073,741,824 bytes.

Simply put, decimal and binary translates to the same amount of storage capacity. Let's say you wanted to measure the distance from point A to point B. The distance from A to B is one kilometer or .621 miles. It is the same distance, but it is reported differently due to the measurement.

Capacity Calculation Formula

Decimal capacity / 1,048,576 = Binary MB capacity

Example:
A 40 GB hard drive is approximately 40,000,000,000 bytes (40 x 1,000,000,000).

40,000,000,000 / 1,048,576 = 38,162 megabytes" ... unquote

In other words, formatted capacity and actual capacity are two different things. They just round the figures up to make it look good in the adverts.  :-D

[HopperJF]

tokyoracer wrote:
The XBOX 360 drive is worse, they say 20GB but it's only 13GB. Very silly.

A lot of that is the XBox Operating System, I know I have one  :-)

[pyrre]

@jorkany

Quote:

    Yes they do. but when calculating anything above 1KB OS's multiply by 1000 making 1GB 102400Bytes instead of 1047576Bytes.


Wrong.

What is correct then?

Quote:

    Well i disagree... the SI standards are made to differ in terms. KB is Kilo Byte and can be interped as 1000 Bytes.


A kilobyte is 1024 bytes, regardless of any effort by marketing boards to redefine it.

Oh really...
one byte is, one... one kilo is one thousand (1000).
1 byte multiplied by 1000 is still one thousand...
K=1000
B=Byte
there is nothing that say it IS calculated binary or decimal!
That is why KiB or KibiB (kilo binary byte) were invented...
It confused some people...