WEBVTT

00:00:00.000 --> 00:00:05.680
Computer storage feels like a ripoff, considering you never get quite as much space as it says

00:00:05.680 --> 00:00:09.840
on the box. The part of the reason for this is something called overprovisioning. But we're

00:00:09.840 --> 00:00:13.600
not going to talk about that today. Not because we're mean, but because we already did a video on

00:00:13.600 --> 00:00:18.480
it. But what we are going to talk about today is another sneaky way that your own drives,

00:00:18.480 --> 00:00:23.760
the ones in your computer right now, steal space from you. If you bring up the properties box for

00:00:23.760 --> 00:00:29.120
any random file on Windows, you'll see a stat called size on disk. And odds are that it'll be

00:00:29.120 --> 00:00:34.480
larger than the field that says size. This means basically what it shows. Most files take up more

00:00:34.480 --> 00:00:40.000
space than they really need to occupy. But why? The answer has to do with how your computer's

00:00:40.000 --> 00:00:45.680
file system stores data. If you're using Windows, its NTFS file system organizes all of its data

00:00:45.680 --> 00:00:50.640
into four kilobyte clusters by default. Aside from making your drive delightful and crunchy,

00:00:50.640 --> 00:00:55.280
discrete clusters like these serve the important purpose of making it simpler for your system to

00:00:55.360 --> 00:00:59.840
keep track of where everything is. In other words, having consistent cluster size reduces the

00:00:59.840 --> 00:01:04.960
overhead of your file system. The downside of this is what we call slack space. In this case,

00:01:04.960 --> 00:01:10.480
if a file isn't an exact multiple of four kilobytes in size, you're going to have some wasted space,

00:01:10.480 --> 00:01:15.360
or slack. You can see this very easily with small Microsoft Word documents, many of which take up

00:01:15.360 --> 00:01:20.240
16 kilobytes on your disk, even though the real size might be a few kilobytes less. A few kilobytes

00:01:20.240 --> 00:01:24.960
of wasted space here and there might not seem like that big a deal. But given how many small

00:01:24.960 --> 00:01:30.160
files are on the typical SSD, it really starts to add up. Not to mention that many of these small

00:01:30.160 --> 00:01:34.800
files are system files that Windows needs to run, so it's not like you can just get rid of them.

00:01:34.800 --> 00:01:39.120
But the good news here is that slack space is unlikely to have a massive effect on your drive

00:01:39.120 --> 00:01:44.000
unless you are really hurting for those last two megabytes. And that four kilobytes is a relatively

00:01:44.000 --> 00:01:48.880
small cluster size compared to other file systems, such as one commonly found on USB flash drives.

00:01:48.880 --> 00:01:53.200
But with flash drives being smaller than the typical SSD, why the heck do they have bigger

00:01:53.200 --> 00:01:58.160
cluster sizes and more wasted space? Although flash drives can use a variety of file systems,

00:01:58.160 --> 00:02:03.760
really any file system, XFAT is popular among modern devices. Despite it having a name that

00:02:03.760 --> 00:02:09.520
makes it sound more like the next trendy diet. Unlike NTFS, XFAT has clusters of between 32 and

00:02:09.520 --> 00:02:14.480
128 kilobytes. Although you might immediately think that that would result in more slack space,

00:02:14.480 --> 00:02:18.240
and you would be right, there are some real benefits to arranging the files this way.

00:02:18.240 --> 00:02:23.040
Like other file systems, XFAT has to keep track of which clusters are free and which are used.

00:02:23.120 --> 00:02:28.720
And this information also takes up space on the drive. So fewer, larger clusters means a smaller

00:02:28.720 --> 00:02:33.440
cluster record. As far as the concern about more slack space, it's less of a space hog if you

00:02:33.440 --> 00:02:37.760
only have a relatively small number of large files, which is exactly what many kinds of

00:02:37.760 --> 00:02:42.240
flash drives are used for, such as the SD cards and cameras that store high resolution images.

00:02:42.240 --> 00:02:47.360
XFAT also differs from NTFS in that it doesn't keep a journal. Basically, that's a log of changes

00:02:47.360 --> 00:02:51.680
that helps the file system recover in the event of a crash. Journaling takes up precious space,

00:02:52.080 --> 00:02:56.480
XFAT doesn't bother with it. Instead, XFAT uses large clusters so that if there's some kind of

00:02:56.480 --> 00:03:01.280
unexpected failure, such as yanking the drive out of the USB port while it's busy, chances are a

00:03:01.280 --> 00:03:05.760
smaller number of clusters overall will be affected. I guess the moral of today's story is that,

00:03:05.760 --> 00:03:10.320
no, the computer storage industry isn't out to rip you off in the way that you think it is,

00:03:10.320 --> 00:03:16.080
though I still wouldn't blow 40 bucks on an SSD water block. I can't believe those exist.

00:03:16.080 --> 00:03:22.080
Thanks for watching guys, like, dislike, check out some of our other videos, comment with video suggestions down below and don't forget to subscribe and follow.