Storage Solutions What is the actual capacity of WD 640GB??

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This is because the hard drive manufacturers say a gigabyte is 1000 megabytes, and 1 megabyte is 1000 kilobytes, rather than 1024 like windows reads it.

HDD makers define "GB" or "Gigabyte" as 1,000,000,000 bytes. Microsoft (in Windows) defines it as 1,024 x 1,024 x 1,024 bytes, or 1,073,741,824 bytes.

So what the manufacturers sell is 640 gigabytes using the "decimal" giga, not the "binary" giga.

640 x 1000 = 640 000 "megabytes"

640000 x 1000 = 640 000 000 "kilobytes"

640 000 000 x 1000 = 640 000 000 000 "bytes"

BUT the computer reads this number in binary! So 640 000 000 000 bytes divided by 1024 = 625 000 000 kilobytes, not 640 000 000!

625 000 000 divided by 1024 = 610 351.56 megabytes

610 351.5625 divided by 1024 = 596 gigabytes.
 
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do a quick calc

640 x 1000 x 1000 x 1000

This is the no. of BYTES

now divide above as

BYTES / (1024 x 1024 x 1024) This will give you Traditional Gigabytes i.e. 596 GB

edit: Meh, we are all post freaks, all inside 60 secs...
 
No, its how HDD manufacturers calculate capacity - millions of bytes, as against what we think - megabytes. thats where the disconnect happens.
 
I wonder why everyone doesn't adopt the same standard and stick to you? Or is it difficult for hardware manufacturers to adopt the binary and for software makes to adopt the decimal version?
 
somebody should tell the manufacturers that 1GB = 1024MB and not 1000MB.....maybe they didn't took their computer lessons properly :D
 
Actually they did.
Its only logical to us followers of the metric system that 1000MB = 1 GB

The friggin americans messed up with their imperial system. 1024MB = 1GB
Doesnt make sense. :P

SI clearly defines Giga as 10^9. Not in powers of 2. First chapter of even a sixth grade physics text book.
 
shaunak said:
Actually they did.
Its only logical to us followers of the metric system that 1000MB = 1 GB

The friggin americans messed up with their imperial system. 1024MB = 1GB
Doesnt make sense. :P

SI clearly defines Giga as 10^9. Not in powers of 2. First chapter of even a sixth grade physics text book.
Click to expand...

what 6th grade physics text book does teach is that computing takes place in bits n bytes...
a computer doesnt understand anything beyond binary....that is 1 n 0 ...n hence the counting is in the power of 2 n nt in 10(decimal)

1024 comes from binary n nt from imperial :)
 
Yes. But you can definately count data for representation in Metric (since it is internationally accepted), so that a bunch of people dont feel that their HDD manufacturers have conned them.

Or manufacturers could agree to market drives as 596GBs.

I personally prefer the metric system.
 
^^ that is not feasible since 596MB x1000 =! 596GB

also 596KB x 1000 =! 596MB

the whole idea of metric multiplication would make no sense this way...

also bandwidth n data transfer takes place in bits per sec in most digital media.

for that...base 2 (binary) is the only option available...any other base...i.e. hex or octa will be obtained from binary conversions itself...(wid nibbles)

having different standards for data transfer n different standards for data storage will increase the work load n thereby decrease the efficiency of any involved system...(since the conversion has to be taken place at both transmitting n receiving end)

its similar to music... an octave it better left octave...its double work if u try converting octave to decade....

these have been practiced keeping simplicity in perspective....:)

understanding the binary conversion will be much simpler than converting the whole computing to decimal :)
 
goodakash said:
somebody should tell the manufacturers that 1GB = 1024MB and not 1000MB.....maybe they didn't took their computer lessons properly :D
Click to expand...

It's not like that...........
It's just a marketing strategy to make more profit.............
 
The easiest way to find out is to calculate the original capacity into 7% approximately. It always will give you an approximate figure of how much Windows will read it as. I read about it many yrs ago on some website and this method of calculation has come in handy with my HDD/Pen drive purchases over the yrs.
 
manusag said:
as the thread title is self explanatory, looking for some quick reply. Windows 7 shows 596 gb in total
Click to expand...

Actually the title is not self-explanatory :P Like people have posted there is "physical" capacity... then there is the remaining capacity after you partition the disk and the partition tables take up some space... then again reduced capacity after you format with a particular OS file-system because the file-system has its own tables and structures, then yet again you can lose capacity depending on the files you store...

If you store a lot of small files you can waste space because the file system typically has a fixed "block size" of say 4 KB... so if you store all your files of size 2KB you will get HALF the storage space :D But usually your files are large so you lose only a small percentage for files after accounting for losses due to partition/FS tables...

Hence your "640GB" drive shows 596 GB total space in Windows.

There was a recent Microsoft employee blog post with a link to the XKCD comic in it: The Old New Thing : Why does Explorer use the term KB instead of KiB?

kilobyte.png
 
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