If you've ever gone to buy a hard drive or SSD, and you went to plug it in,
you may have noticed that something doesn't add up. If it's a 1TB drive,
it'll only show as 931GB. If it's a 2TB drive, it'll only show as 1.81, and so on. So what
gives? Surely this is false advertising by the manufacturers! But actually it's not.
They are telling the truth. The discrepancy comes from the units being used. There are
some other possible reasons I'll mention at the end of the video, but those aren't the main focus
of this video. So first I'll explain why this discrepancy happens, and then we can get into
the philosophical discussion about who's right and who's wrong, because it depends on who you ask.
So let's take a 1TB drive for example. 1TB is equal to 1000GB. Now stop,
because I already see some of you rushing to the comments to say, "It's not a thousand!" Hold on,
I'm going to address that, that's literally the whole point of this video. Now everyone has heard
of kilobytes, megabytes, gigabytes, terabytes, with the abbreviations, KB, MB, and so on.
But have you ever heard of kibibytes, mebibytes, gibibytes, and tebibytes? Yes,
they're actually a thing, and they use the abbreviations KiB, MiB, GiB,
and so on. The difference between them in terms of number of bytes is that megabytes
and the others are powers of 10, whereas mebibytes and the others are powers of 2.
So there's 1024 kibibytes in a mebibyte, 1024 mebibytes in a
gibibyte, and so on. And while they're pretty close in actual numbers of bytes,
the higher you go, the more they diverge. So if you want the spoiler answer to the
question from the beginning of the video, the reason, for example, that a 1TB drive shows
up as 931GB in Windows is that behind the scenes, Windows is measuring the number of
gigabytes or whatever in terms of gibibytes, but it incorrectly displays the labels as gigabytes.
And the same goes for terabytes. It's measuring and displaying the number of tebibytes,
but the units show terabytes. And since a gibibyte is larger than a gigabyte, 1.074 times actually,
if you divide 1000 gigabytes by 1.074, you get that number 931. That's where that comes
from. So if you buy a 1TB drive, you are indeed getting 1 trillion bytes of storage.
Now side note, many people would say that Windows isn't actually wrong in displaying these units,
I'll address that later. Now you might be thinking, wait,
why doesn't Windows use the right units? And why haven't I even heard of these
gibibytes and everything else before? Well, since the early days of computers,
because computers use binary, it's easier to actually deal with numbers in powers of two.
And you probably recognize these numbers, they come up a lot when dealing with computers. And
when they got to 1024 bytes, long story short, people decided, eh, that's close enough to 1000,
we'll just call it a kilobyte. And since every 10 powers of two is close to its
corresponding decimal number anyway, the other prefixes could just be used too.
Except this predictably became confusing with people using the terms of megabytes
and gigabytes and everything else for both the binary meaning and the decimal
meaning. Meaning binary with the powers of two meaning and decimal as the power of 10 meaning,
but still calling them the same thing, gigabytes and megabytes and whatever.
So the IEC, a standards organization came up with those new prefixes to be used for
the binary based units instead, so you could discriminate between them. And they
came up with the names by just taking the "bi" part of binary and sticking that on,
and using that. The problem is those units never really caught on in the mainstream.
They are actually officially recognized though. For example,
the National Institute for Standards and Technology requires the binary prefixes
to be used if you're referring to such units. But as the difference between the binary and
decimal units became larger and more obvious with bigger drives, many companies and people
just started using the decimal meaning only, which is way more intuitive anyway.
And that way they can just keep using the same unit labels. For example, in 2009, starting with
Mac OS 10.6, Macs use the decimal units with their proper prefix. And since at least 2010, the Linux
distribution Ubuntu has also had a policy to use the official units. If you're using a Mac or most
distributions of Linux, then you'll probably see the same number that shows on the box.
I believe hard drive manufacturers have always used the decimal meaning. And
also if you're talking about network speed, like one gigabit per second,
that has always referred to the decimal meaning also. So a big reason why you rarely
see these units and prefixes is because most people aren't using them anyway,
they're just using the decimal meaning of gigabytes. There are some holdouts though,
who are using the binary units, but displaying the decimal label,
namely Microsoft Windows and RAM manufacturers as big ones. At least in Windows, if you do go
to the properties window of a directory or file, it will show you the exact number of bytes,
but for most people I think that is just going to add to the confusion.
So why does Windows do this? Well, if you go back to 2009,
the reasoning was that nobody else was. So okay, fair enough. At the time,
you could make the consistency argument. I mean that blog post was from before Mac
OS had even switched over later that year. But why Windows still does this really confuses me.
And I'm not even saying that I expect them to start using the binary labels,
that would just confuse virtually everyone. Rather behind the scenes, they could start
just showing and measuring in the decimal units and keep the same label. And honestly,
no one would even notice or care. There's not anyone out there who would say, "Wait a minute,
yesterday this Microsoft Word document was 1.28 megabytes and now it's 1.34.
What gives?" Surely a lot of people would notice that their hard drive capacity has changed,
but it would look like their hard drive got bigger. So I doubt they're going to be mad
about it. So if Microsoft is maybe worried that a change after this long would be confusing to
people, well, I would argue there's nothing confusing about plugging in
a drive and seeing the same number that's listed on the box that you're expecting.
I mean, I remember even ages ago buying a 64 megabyte memory card for the Xbox 360
and being pissed when I plugged it in and saw there was only 61, seemingly. Because
back then every megabyte mattered. And even if there is some compatibility issue behind
the scenes with how settings or Windows operates, what you could do is just change
how it's displayed in Windows Explorer only, which is what would matter for 99% of people.
And then just keep using the binary units for any calculations behind the scenes. And you
could even switch those over to use the binary labels. Now I mentioned RAM manufacturers before,
and they also use capacities in powers of two and display the decimal unit
labels. Apparently they do have a legitimate reason for using the binary units at least,
because of the way logical and physical addressing works in memory.
But I still think they should use the right labels and call them the right thing. Finally,
at the beginning, I did mention that there are some other possible causes for why a
drive might show a lower storage capacity, one of them being a hidden partition. A lot
of prebuilt computers will come with a recovery partition that's hidden, and that will make the
main partition show smaller, but that's because it's actually being used for something else.
I've seen some people mention that the operating system will take up space,
but that wouldn't actually reduce the capacity of the drive that'll just show
as space taken up. Others have pointed out that the file system itself, like NTFS, may take up
space on the drive, and while technically true, that would be relatively negligible,
especially the difference compared to the units that's showing differently.
And also, I'm not even sure if that would reduce the total capacity shown,
or if that would also just show as space taken up. In any case, hopefully this cleared something up,
and if you were mad about drives not being as big as they should be, well,
rest assured, you are getting what you pay for. At least most of the time,
there are cases of scam flash drives being sold on Amazon that say it's like 10 terabytes,
but really, they just mess with the firmware, but that's maybe a whole nother video.
So hopefully you learned something. Be sure to give this video a thumbs up if you enjoyed it,
let me know down in the comments what you think. Did you know about this before?
Maybe you're a computer genius, and you did. Also maybe consider
checking out some other recent videos on my channel, and maybe subscribe.
If you do, be sure to click the bell to enable all notifications. These days, even if you subscribe,
YouTube still might not show you the videos. If you want to keep watching,
the next video I'd recommend is where I talked about secrets of the Windows calculator. There's
a lot about it that you might not know about, so I'll put that link right there.
So thanks so much for watching guys, and I'll see you in the next one.