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Thread ID: 98025 2009-03-08 07:14:00 Hard drive question, please? ianhnz (4263) Press F1
Post ID Timestamp Content User
754712 2009-03-08 07:14:00 I purchased a preloved Maxtor 40 GB hard drive off Trade Me. It is formatted as NTFS. can someone please tell me why Windows says it's 38.2 GB's and not 40? Thanks, Ian. ianhnz (4263)
754713 2009-03-08 07:30:00 Basically, in simple terms,

Your operating system usually sees a binary representation of hard drive space whilst a hard drive manufacturer uses the decimal representation.

i.e Decimal Representation of 1kb=1000bytes

Binary Representation of 1kib=1024bytes

The slight difference adds up to a bit more when you get to bigger stuff, such as 40-1000gb HDs

Personally I think its just a scam from HD manufacturers to make their drives look bigger. But the whole picture is incredibly complicating...

HTH
Blam
Blam (54)
754714 2009-03-08 07:41:00 And you'll never use all of a hdd. No matter how big it is Speedy Gonzales (78)
754715 2009-03-08 07:51:00 Ok, thanks. So it's more of a math program than am issue with the drive? Wasn't sure if it was something to do with a "mirror file" after formating. I think that "quick' formating produces a mirror image, of some sort.:thumbs: ianhnz (4263)
754716 2009-03-08 07:57:00 It's a marketing problem really - hard drive manufacturers making their drives sound bigger than they actually are, by using a different measurement. somebody (208)
754717 2009-03-08 08:06:00 Ok, thanks. So it's more of a math program than am issue with the drive? Wasn't sure if it was something to do with a "mirror file" after formating. I think that "quick' formating produces a mirror image, of some sort.:thumbs:

What do you mean by "Mirror image"?


It's a marketing problem really - hard drive manufacturers making their drives sound bigger than they actually are, by using a different measurement.

Thats arguable actually-If you use the decimal system you know exactly how many bytes your HD will be able to hold, while with a binary system you will have to calculate how many bytes your HD can hold....
Blam (54)
754718 2009-03-08 08:10:00 Thinking back to my dos days, if you did a 'quick' formate you could run 'unformat' to restore. Don't know if Windows does that too.:confused: ianhnz (4263)
754719 2009-03-08 08:15:00 Would be good if it could-but sadly it can't:(

But-IIRC a quick format only deletes the files in the partitions, so if you don't use the space, you can probably recovery everything to its original state using a file recovery program.
Blam (54)
754720 2009-03-08 08:16:00 A bit OT, but anyway... There is a way to calculate how much space you actually get, based on the marketed capacity:

Marketed capacity / 1.024 / 1.024 / 1.024 = Actual Usable Capacity
jwil1 (65)
754721 2009-03-08 08:20:00 I forgot where-but I read somewhere that the easiest way to do it, without a calculator is 0.93 x capacity of HDD from manufacturer for Hds less than a terabyte and 0.91x capacity of Hds 1 terabyte and beyond.

Its usually quite accurate
Blam (54)
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