When you buy a hard drive, somewhere about the capacity of the drive you are buying, (Say 500 GB) is the disclaimer, “actual formatted capactiy is less.” This has pissed me off for a very long time – not so much because we’re getting gypped storage (we are) but because the computer industry counts on our collective inability to comprehend even the basics of mathematical facts such that they can get away with promoting the bullshit idea that after you format a hard drive, the amount of space on the disk dwindles considerably. But why would formatting take up so much space? And if it was a question of formatting, why doesn’t the format affect all drives equally? For example, a 200 GB hard drive actually yields 186.3 GB of usable space. A 500 GB HD should therefore have 486.3 GB of usable space, right? Because drive formatting should take up the same amount of space on each drive, right? Wrong. A 500 GB hard drive gives you 465.7 GB of usable space. That’s 13.7 GB of space eaten up on the 200 GB HD and 34.3 GB of unusable space on the 500 GB HD due to “formatting.” What the fuck is going on here??
I’ll tell you what is happening. The computer companies know how bad we suck at math, but even as pertains to basic math, people are scared of fractions and very large numbers. As a teacher I have tried to explain the phenomenon that is this loss of HD space, but I don’t seem to get through to them. So I am going to try again, and i hope those of you who didn’t understand thnis before will understand now.
I’m going to make an example first. Let’s say there is a burger joint in town called Harry’s Hamburger Hut. They make the most delicious burgers in town for $10. What is really cool about this place is that if you want to buy a fraction of a hamburger you can. So if you have $5, you can buy 1/2 a hamburger. If you have 2.50, you can buy 1/4 of a hamburger. If you have $1, you can buy 1/10 of a hamburger. In this case, the numerator (that’s the top of the fraction for all you muckleheads – that’s math knuckleheads) represents the amount you have, and the denominator (bottom) is the cost of one. So if you have $8, you can get 8/10, or in lowest terms, 4/5, or as a decimal, .8 of a hamburger. What can you get with $35? 3 and a half hamburgers, because 35/10 = 3.5.
Now I am going to relate this to hard drives. Please don’t be scared by the large numbers. The most difficult concept here will be division.
Computers interpret binary which is a series of 0s and 1s to represent characters, instructions/etc. Because the only choices are 0 and 1, everything is on a base 2 system, meaning storage blocks and such are always a power of 2. So 2 to the first power, 2 squared (which we will represent using 2^2) 2 cubed (2^3), 2^4, 2^5, and so on.
Now the prefix kilo means 1,000 Back when we were on kilobytes of storage, they noticed 2^10, which = 1024, was close to a kilobyte. So they had computers interpret 1 KB as being 1024, not 1000.
They did the same thing with Megabytes. Mega means 1 million, or 1,000 thousand. But if one KB is 2^10 = 1,024, the one MB is 2^20 = 1,048,576. So 1 MB is interpreted by a computer as being 1,048,576 instead of 1,000,000.
Guess what, they did the same thing with Gigabytes. Giga means 1 billion. Because of the way a computer sees it, you don’t have a GB until you have 2^30 = 1,073,741,824 bytes. Kind of like if you have $9, the salesman at Harry’s Hamburger Hut doesn’t think you have enough for a full hamburger until you have $10.
So when a hard drive manufacturers sells you a 500 GB hard drive, he/she is giving you 500 ACTUAL gigabytes, meaning 500,000,000,000 bytes. If you want to see what that would give you in computer gigabytes, then do what you did at the hamburger hut. Divide the number of gig you have (500,000,000,000) by the amount of space allocated to each gigabyte in a computer (1,073,741,824). 500,000,000,000/1,073,741,824 = 465.7! (see first paragraph) which you will notice is the exact “formatted” capacity.
And just to keep us updated with the times, we are now in terabytes – tera means trillion. That’s a one with twelve zeros: 1,000,000,000,000. But to a computer, a terabyte is 2^40, or 1,099,511,627,776 bytes. So if you get a 2 TB hard drive, you are getting the 2 trillion bytes, divide by 1,099,511,627,776, which is actually 1.81 TB. You’re losing 190 GB not because of “formatting,” but because HD manufacturers are dishonest pricks. We need to demand that these cocksuckers give us the number of bytes as recognized by the computer, or at least stop saying stupid shit like “actual formatted capacity is less.”