cryingvalor

-hey guys whay is it that a 40 GB HDD is not exactly 40 GB. i have a 80 GB seagate HDD and when i check its capacity its around 74 GB only where did the 6 GB go?

blackduck30

The hard drive capacity is a general volume capacity that is before formatting, each manuafacturer will round there drives up to the closest general volume. You also loose some volume after the drive is formatted, this is not really that much and the majority is the manuufacturer rounding the drive up

TheMatt

Also, laptop hard drives commonly have a restore partition that takes up around 2 - 3 GB.

EDIT: Wow, just one minute after!

cryingvalor

-what do you mean by this

hwm54112

Operating systems define a gig as 1,073,741,824 bytes while drive manufacturers define a gig as 1,000,000,000 bytes ( which is actually .93 gigs). So rather than call a 93 gig drive a 93 gig drive, manufacturer’s round the size up to 100 gigs (a nice even number).

I believe it’s a throw back to the early days of hard drives. As an example, all drives were manufactured to be, let’s say 18 meg drives- after production, the drives were tested for bad sectors. The drives that had 15 megs of usable sectors were sold as 15 meg drives, while those that had only 12 usable megs were sold as 12 meg drives and those that had only 11 megs of usable sectors were sold as 10 meg drives with the bad sectors being marked so that they wouldn’t be used. In this example, 10, 12 and 15 meg drives were exactly the same as manufactured but some had less usable space because of manufacturing inefficiencies.

Intel used to do the same with processors. For example, all early P4’s were exactly the same as manufactured. After production, each cpu was tested at ever increasing speeds until it began to fail. Intel would then sell the processor as having the speed at which it stopped functioning properly less a certain percentage for safe measure. That fact is part of what enabled overclocking of some cpu’s.


Bill

cryingvalor

- isn't that consider a factory defect and its like they are not selling a 100% working product.

8210GUY

It's more a conversion error if you like along with the above, in a way it is cheating, but people seem to have accepted it or they would of changed it I guess, that and peoples laziness, what is easier to say, 1.024 gig or 1 gig ?, especially when you add that up for say a 500 gig drive, but if you convert anything it is only as accurate as the formula you used, I often had arguments with a midwife telling them their charts for pounds to kilo's was wrong, but they wouldn't have it, eventually I showed them a bag of sugar, they finally understood what I was telling them about rounding up, (they had it wrong lol).

hwm54112

I wouldn't think of it as a factory defect- it was the best manufacturing technologies could do at that time. And they did sell a fully working product. When you paid for a 12 meg drive you received 12 megs of working disk space. Bad sectors do not mean a drive is bad. All drives have bad sectors. It's my understanding that as sectors go bad on a drive, those sectors are marked as bad and remapped to extra sectors that are on the drive. So, at the end of the day, you get what you pay for.

Back then, each drive sold with a hand written list of the the bad sectors. Because people didn't (and still don't) understand that bad sectors don't equate to a bad drive, those bad sector maps were eliminated because consumers thought they were buying defective drives.

It remains a common misconception- you'll find a number of posts wherein someone says chkdsk found a bad sector and he will be advised to back up his data-the drive is dying. It's just not the case. a gig has over 4,000,000 sectors. even if a thousand are bad, it's a miniscule fraction of it's capacity.

When you get down to it, it's just a word definition or a math calculation and nothing more.