Why storage media don't say how much they really store...or do they?

[lomk 20,663]

WARNING: BIG NUMBERS AHEAD.

If you don't like big numbers or math, then I suggest you don't read this as it may leave you with headaches. You may even begin to ponder the answer of life, the universe, and everything (by the way, it's forty-two). CONSIDER YOURSELF WARNED

 

Now that we've got that out of the way, let's move on to the meat of this topic, shall we?

 

Now, I've always asked myself the question: Why is it that when I buy a storage device that I don’t get the amount of memory it advertises? When I get a 2 gigabyte flash drive, it's only 1.86 gigabytes. Or when I get a 320 gigabyte hard drive, it's only 298 gigabytes. Why does that occur? Why don't I get 320 gigabytes when I'm paying for 320 gigabytes?

 

You may think you’re not getting the memory you purchased. It would be completely understandable to the average person to be upset for missing out on a potential 22 gigabytes of data the hard drive says it has. Most people will pick up a storage medium, such as a flash drive, and notice that although the package specifies that the device may have the capacity of, say, 2 gigabytes, you might look in Windows and notice it only stores 1.86 gigabytes. This is a subject that has confused me forever, but I think I've finally figured it out (without Google).

 

Our understanding of the metric system runs with the idea of base 10 prefixing. In other words,

Kilo = 1,000

Mega = 1,000,000

Giga = 1,000,000,000

Tera = 1,000,000,000,000

And so forth…

 

Now, have you heard of the term “8-bit?” In its most general sense, it’s used to describe an era of video games and a generation of microprocessors. Why don’t we ever see computers running something like a 60-bit or 30-bit processor? That’s because the computer does not run in the base 10 system of metric prefixes that we all learned in middle school and have been adjusted to throughout our lives. Instead, computers run in the base 8 system of metric prefixes. Why is this? Although I haven’t done any research into it, the most obvious reason I can find is that 1 byte equals 8 bits. How do I know this? Well I know Notepad uses 8 bit characters. If I type one character and save the text file, it is only going to be one byte in size (although, thanks to Microsoft's File Allocation Table, or FAT, it's going to take up 4,096 bytes on my disk). Try it for yourself. Surely you have 4,096 bytes on your drive to spare.

 

Moving on...

 

So what does this mean? It means the divisors of our metric prefixes have changed now! It’s not much of a difference starting with “kilo” but as we move up, it’s quite a drastic change because now, instead of multiplying by 1,000 to get to the next prefix, we multiply by 1,024. In other words,

1 kilobyte = 1,024 bytes

1 megabyte = 1,024 × 1,024 = 1,048,576 bytes

1 gigabyte = 1,048,576 × 1,024 = 1,073,741,824 bytes

1 terabyte = 1,073,741,824 × 1,024 = 1,099,511,627,776 bytes

  

Now, since our minds are stuck in the base 10 system of metric prefixing, we think that a 2 gigabyte flash drive should have 2,000 megabytes of storage, which would mean 2,000,000,000 bytes of storage (in the base 10 system, of course). And in fact, it does! The flash drive I currently have loaded in my computer stores 1,999,597,568 bytes of data (as illustrated by the picture below). However, since computers do not run in the base 10 system of metric prefixing that we all think they do, the number is not divided by 1,000,000,000. It is, instead, divided by 1,073,741,824. With a difference in the divisor being in excess of 73 million, there is bound to be a considerable difference in the quotient.

 

 

This should work every time. Load your storage device, go to Computer, and find your device. Right click it and pull up Properties. Look where it says “Capacity” (the circled number in the picture). Divide that number by the corresponding prefix mentioned above. Do the numbers match when you convert bytes to kilobytes, megabytes, gigabytes, or terabytes?

 

I divided 1,999,597,568 by 1,073,741,824 (the divisor that changes bytes to gigabytes). Do you want to know the answer?

 

1.862270355. That rounds (to two decimal places) to 1.86.

 

I’ll do the same with my 320 gigabyte hard drive.

 

320,070,479,892 ÷ 1,073,741,824 = 298.0888633914. Rounded to the nearest whole number, it’s 298.

 

Anyway, in case you pick up that flash drive and the package says 2 gigabytes but your computer only says it has 1.86, that's why. I hope this post was informative and helpful! 

 

In my opinion, I do think we're all getting cheated out of memory we pay for. If I pay for 320 gigabytes, I should get enough bytes to equal 320 gigabytes, not enough to be 320 billion bytes. But nobody's sued the companies yet. Besides, I'm not upset. I'm still far from using all 320 gigs. Regardless, I hope that this post gives you some insight when you buy your next storage medium!

Edited April 22, 2013 by ThatOneBrony

[Zygen 6,065]

This is something I've always kinda been curious about, i just assumed that some random something else got stored on it. So thanks for clarifying, always nice to learn something new .

 

It is kinda annoying they get to cheat people out of memory though , but at the same time i'm normally fine on memory when I buy storage devices anyways, still can be annoying.

[lomk 20,663]

This is something I've always kinda been curious about, i just assumed that some random something else got stored on it. So thanks for clarifying, always nice to learn something new .

 

It is kinda annoying they get to cheat people out of memory though , but at the same time i'm normally fine on memory when I buy storage devices anyways, still can be annoying.

Me too! I used to think it might be some stuff the computer uses to be able to read and write to the drive. Until I noticed something fishy when I was cleaning up my hard drive....why does it say 320 billion bytes? Well, there ya have it! But yeah, like I said, if I'm paying for 320 gigabytes, I don't want 320 billion bytes. I want 320 gigabytes lol oh well. I'm only using 120 after all my iTunes and video games got put on there so I'm still good. 

[Diamond Treasure 118]

You do know there is a program hidden in things such as flash drives that takes up a very very small amount of memory because if it wasnt there flash drives would be useless because the computer wouldnt be able to read it right

[lomk 20,663]

You do know there is a program hidden in things such as flash drives that takes up a very very small amount of memory because if it wasnt there flash drives would be useless because the computer wouldnt be able to read it right

I'm sure you're right about that. And that may be why my computer said it has 1,999,597,568 bytes instead of the 2 billion that one would expect with the prefix giga- lol

 

...OH MY GOD! I think I coined a new word!! gigalol

[Lost 1,409]

The problem is not with the Hard-drive/storage media manufacturers. Gigabyte means 1,000,000,000 bytes, but operating systems work on it meaning 1,073,741,824 bytes which means that the is a perception of lost space but in actual fact the manufacturer has the correct size and it is the software that states it incorrectly.

 

I'll do this with small numbers, you must remember that kilo means thousand, 1kilogram is 1,000 grams, kilo always means thousand and it does in some parts of computing, kilobyte literally means 1,000 bytes, but in some areas of computing it means 1,024 bytes, the former is the standard that manufacturers of hardware use whereas the latter is what software developers use.

 

Flash drives tend to have more "missing" than disk drives because of firmware.

 

Here is a screenshot of 5 of my Hard-drives. The OS Drive is an SSD, the others are all physical drives, with the portable being an external drive.

 

The X, K and F drives are all the same size (1TB) but as you see, the K drive (portable) shows as having less bytes.

 

Edited April 22, 2013 by Lost

[Betez 1,734]

I always thought computers ran on base 2, or binary. Maybe I'm confused.

 

Whatever, this has been something that has pissed me off for awhile, but especially with apple products. When I got my iPod touch back in 2011, it said it had 8 gigs of HD space, but in fact, it doesn't even have 7. I think that's just more of Apple's stupid logic, though.

 

Interesting topic though. I never thought about that.

Edited April 22, 2013 by Betez

[lomk 20,663]

The problem is not with the Hard-drive/storage media manufacturers. Gigabyte means 1,000,000,000 bytes, but operating systems work on it meaning 1,073,741,824 bytes which means that the is a perception of lost space but in actual fact the manufacturer has the correct size and it is the software that states it incorrectly.

 

I'll do this with small numbers, you must remember that kilo means thousand, 1kilogram is 1,000 grams, kilo always means thousand and it does in some parts of computing, kilobyte literally means 1,000 bytes, but in some areas of computing it means 1,024 bytes, the former is the standard that manufacturers of hardware use whereas the latter is what software developers use.

 

Flash drives tend to have more "missing" than disk drives because of firmware.

 

Here is a screenshot of 5 of my Hard-drives. The OS Drive is an SSD, the others are all physical drives, with the portable being an external drive.

 

The X, K and F drives are all the same size (1TB) but as you see, the K drive (portable) shows as having less bytes.

 

1b58651cbbd1b35a71fcb7b14f29a538.png

Well then, that certainly does make a lot more sense now that you put it that way. I guess Windows is weird like that, reading things in divisions of 1,024. It may be because of its file system. Because now that I think of it, I've run Ubuntu on this same HDD and it's read it as a 320 GB drive. *shrugs* But yeah, I was just reporting my observations lol This would make a great discussion topic with my computer forensics professor! 

 

Also, do you mind telling me the name of your Chrome theme? It's so full of win and fits with my darker Windows theme!

[Lost 1,409]

Well then, that certainly does make a lot more sense now that you put it that way. I guess Windows is weird like that, reading things in divisions of 1,024. It may be because of its file system. Because now that I think of it, I've run Ubuntu on this same HDD and it's read it as a 320 GB drive. *shrugs* But yeah, I was just reporting my observations lol This would make a great discussion topic with my computer forensics professor! 

 

Also, do you mind telling me the name of your Chrome theme? It's so full of win and fits with my darker Windows theme!

 

 

Its actually an My Little Pony theme, it is called Luna Theme by PonyThemes. Not sure if this link will work but here it is anyway:

https://chrome.google.com/webstore/detail/luna-theme/pmhihobegibbfdeogahppfhmbfmbjann?hl=en

[A Blithering Div 247]

You also have to factor in formatting as simply having a formatted drive will reduce its overall capacity. Also I remember Seagate, an HDD manufactorer first using metric for its measurements of drives. First to be sued over it too. So now we have the "ibbies" such as kibbybyte (KiB) to denote its binary nature.

 

Also, XKCD

 

The problem is not with the Hard-drive/storage media manufacturers. Gigabyte means 1,000,000,000 bytes, but operating systems work on it meaning 1,073,741,824 bytes which means that the is a perception of lost space but in actual fact the manufacturer has the correct size and it is the software that states it incorrectly.

 

Not true. Old hard drives use binary factors where 1 Gig of HDD space will read as 1 Gig to Windows and other OSes that recognize a KB as 2^32. This was done purely for marketing reasons.

[Circadian 1,273]

I always thought that they just used an approximation for all that stuff. Like, my hard drive isn't exactly what is said on the box.