Instructor: In this lesson, we're going to talk
about form factors.
Now the form factor of a motherboard describes its shape,
layout and the type of case and power supply
that can be used with that particular motherboard,
as well as the number and type of adapter cards
that can be installed within that motherboard.
When you're building a custom PC,
you're going to pick out your motherboard first
because everything else is going to be based
upon that motherboard.
When you pick your motherboard,
it's going to tell you how many memory modules you can support,
how much memory you can support,
what type of storage connectors you have
such as SATA or PATA or IDE or even SCSI,
depending on which motherboard you pick.
This is why it's important to always consider
the form factor of that motherboard first.
Now, motherboards come in a variety
of different form factors.
These include ATX, mini-ATX, micro-ATX and mini-ITX.
Let's talk about each of these briefly.
First, we have ATX which stands
for the Advanced Technology eXtended.
Now ATX motherboards have been around for a very long time
and they started out all the way back in the 1990s.
These motherboards are considered a full size motherboard
and they measure about 12 inches by 9.6 inches in size
which translates to about 305 by 244 millimeters.
When you look at an ATX motherboard,
they're going to have their expansion slots
running parallel to the shorter side of the board
which measures that 9.6 inches.
And they'll also have a rear report cluster
which has integrated port for things
like audio, video, sound, networking,
and other features like that.
Now because ATX is a very large size motherboard,
it only works in larger towers and cases.
So there was another version
of this created called the mini-ATX.
Now the mini ATX form factor is smaller
in size than the regular ATX form factor
but it still contains a lot of the same features
that you find in a regular ATX motherboard.
This includes the rear port cluster for integrated ports
as well as expansion cards that run parallel
to the side of the board.
With the mini-ATX, you're going to find it measures
about 11.2 inches by 8.2 inches in size,
and those expansion card slots
are going to run parallel to the shorter side of the board.
If you're measuring this in metric,
this is about 284 millimeters by 208 millimeters in size.
In general, you're not going to see mini-ATX used very often
because it is almost the same size as a full size ATX board.
And so the ATX itself was much more popular than mini-ATX.
Now to give us a smaller board,
there's another type of ATX created
called mATX or micro-ATX.
The micro-ATX board measures 9.6 inches squared.
That means it's 9.6 inches on both sides,
which is the smaller size of the full size ATX board.
This measures 244 millimeters by 244 millimeters,
and again, it is a square board configuration.
When you look at a micro-ATX,
it has all the same characteristics
as a full size ATX except,
instead of having up to seven expansion cards,
we only have four expansion card slots
because of the smaller case size.
Now, regardless of which version of ATX you're using,
whether it's full size, mini or micro,
they all can be put into any full size ATX case
because they do have the same screw holes that will line up
and allow it to be mounted in those cases.
Now, in addition to ATX,
we also have another type which is known as ITX.
Now, ITX stands for Information Technology eXtended.
And this was actually a specification that was designed
as a replacement for ATX
and there was a full size equivalent
but it was never commercially produced.
Instead, they went right to what is known as a mini-ITX.
And a mini-ITX measured 6.7 inches by 6.7 inches
providing a small square case with only one expansion slot.
If you're measuring this in millimeters,
this is about 170 by 170 millimeter squared.
Now the purpose of these mini-ITX
was to be able to be used in small cases.
And because of this mini-ITX was used extensively
in small form factor PCs,
but it still does use the same screw mounting holes
that you would use with an ATX board.
So even if you have a full size ATX case,
you can still mount a mini-ITX into that ATX case.
Just like the ATX variance,
mini-ITX does use an integrated rear port cluster
as well as having expansion slots
that run parallel to the shorter side,
which in this case is a square of 6.7 inches.
Now, when you look at ITX as a category of form factor,
there's also a couple of other ones
that are smaller than this.
And these are known as nano-ITX, pico-ITX and mobile-ITX.
These three form factors don't have a designated shape
or size with them because they're actually going to be built
for embedded systems and portable devices
instead of using them for personal computers.
So they're actually going to be built
based on the specific device you're trying to create,
such as a smart TV or a smart speaker
instead of having a standard size
like you have with a mini-ITX.
So when it comes to form factors,
the most important thing to remember
is that the form factor describes the shape, layout
and type of case and power supply
that's going to be used by your system.
When you choose that motherboard,
you're going to have a defined form factor
and that's going to dictate a lot of the other things
that you're going to be able to select
for that particular computer.
Remember, we have ATX and ITX
as our two big categories.
And ATX has the full size ATX, the mini-ATX, the micro-ATX.
And when we look at the ITX category,
we really only focus on the mini-ITX
which is commonly used in a lot of computers these days.