All language subtitles for 4_Pysical Storage - Hard Drives

Before we get into
computer storage,

we need to fill in some gaps.

I'm referring to things
like gigabytes, bits, etc.

But we actually
haven't talked at

all about what
those metrics mean.

Sorry, I got a gigabit
ahead of myself.

As you might have
guessed, these terms

refer to data sizes.

The smallest unit of a
data storage is a bit.

A bit can store
one binary digit,

so it can store a one or a zero.

The next largest unit of
storage is called a byte,

which is comprised
of eight bits.

A single byte can hold a
letter, number or symbol.

The next largest unit is
referred to as a KB bite.

But we typically use
the term kilobyte.

A kilobyte is made
up of 1,024 bytes.

Here's a quick data
conversion chart.

How much does 500
gigabyte even mean?

Let's take a look at the size
of an average music file,

which is about three megabytes.

On a 500 gigabyte machine,

that's approximately
165,000 music files.

That's a lot of music.

We saw all of our computers
data on our hard drive,

which allows us to
store our programs,

music, pictures, etc.

Have you ever had an issue
with your computer and

lost all the data that
was on your hard drive?

Yeah, me too. It was the worst.

This actually happens a
lot and you'll probably

encounter it as an IT
support specialist.

Make sure you backup
your data to be safe.

This means you should copy
or save your data somewhere

else just in case something

goes wrong and your
hard drive crashes.

That way, you won't
lose all your data.

There are two basic hard
drive types used today.

Hard disk drives or HDDs uses

a spinning platter and

a mechanical arm to read
and write information.

The speed that the
platter rotate

allows you to read and
write data faster.

This is commonly referred to as

RPM or revolution per minute.

A hard drive with a
higher RPM is faster.

So if you go out and
buy a hard drive today,

you might see something like

a 500 gigabyte, with 5,400 rpm.

HDDs are prone to

a lot more damage because

there are a lot of moving parts.

This susceptibility to damage

went away with a new type of

storage called solid
state drive or SSD.

SSDs have no moving parts.

Are you familiar
with a USB stick?

SSDs operate in a similar way.

The information is stored on

microchips and data travels
a lot faster than HDDs.

The form factor for SSDs is also

slimmer compared to
their HDD cousins.

Sounds great, doesn't it?

So why doesn't
everyone use SSDs?

Well, both have
their pros and cons.

HDDs are more affordable,

but they're more
prone to damage.

SSDs are less risky when
it comes to losing data,

but they're also more expensive.

So you may not buy as
much memory storage in

SSDs than what you
can get in HDDs.

Believe it or not,
there are even hybrid

SSD and HDD drives out there.

They offer SSD performance

where you need it for things
like system performance,

such as putting your computer

along with hard disk drives,

but less important stuff
like basic file storage.

There are a few interfaces that

hard drives use to
connect our system.

ATA interfaces are
the most common ones.

The most popular ATA drive
is a Serial ATA or SATA,

which uses one cable
for data transfers.

SATA drives are hot swappable,

great term, don't you think?

It means you don't
have to turn off

your machine to plug
in a SATA drive.

SATA drives move
data faster and use

a more efficient cable like this

one than its predecessors.

SATA has been the de facto
interface for HDDs today.

But people quickly found that
using the SATA cable wasn't

good enough for
some of the blazing

fast SSDs that were
coming on the market.

The interface
couldn't keep up with

the speeds of the newest SSDs.

So another interface
standard was created called

NVM express, or NVMe.

Instead of using a cable to

connect your drive
to your machine,

the drive was added
as an expansion slot,

which allows for
greater throughput

of data and increased
efficiency.