HANDOUT – Motherboard Form Factors Objective
101.02
What are the different types of motherboards?
Introduction to Motherboards
A motherboard (MB), also known as a Mainboard,
system board or logic board, is the central or primary
circuit board in a Personal Computer (PC). It is an
extremely complex electronic system that every device
in a computer system connects to in order to send and
receive data. A typical motherboard is made up of a
main microprocessor, called the CPU, two or more
DIMM slots to hold memory modules, support chips
called the Chipset, controller ports for connecting
storage drives, expansion slots for adding connections,
and integrated input and output ports for connecting
external devices.
Motherboard Form Factors
The size, shape and configuration of integrated devices of the motherboard is called the form
factor. Through the history of PC’s, motherboards have been available in many forms, sizes,
shapes, names, brands and purposes. The
original PC motherboard created by IBM is
called the PC/XT. This MB became the defacto standard that many companies cloned.
The open architecture allowed others to
copy the design, electronics, layout and
concept legally. This greatly increased the
knowledge, technology and sharing of ideas
within the PC industry. The XT MB fit into a
case built specifically for the ports and
expansion bus integrated into the MB.
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HANDOUT – Motherboard Form Factors Objective
101.02
The next form factor released was the AT
(Advanced Technology) in 1984. This IBM styled
MB helped the PC to boom. It is easy to recognize
this MB for it has a large keyboard connector
(standard or DIN, 5-pin) and power from the
power supply connects with a P8 and P9
connector. This MB also became known as the
IBM-Clone.
In 1995, the next generation of MB was developed. The
ATX (Advanced Technology Extended) form factor was
released by Intel. It was a completely different MB
style. The CPU is placed on one end with the DIMM
slots to the right and the back panel connectors to the
left. The expansion slots are on the opposite side of the
board. The power connector and hard drive controllers
are on the right side of the board. This form factor
required a different case style and power supply
connection. Both the case and the power supply style
followed the ATX form factor name. The advantage of
the ATX MB is that it made the MB more user-friendly
for the system builder.
The micro ATX, is smaller in size than the original ATX
but it still maintains the same basic layout of ports and
components. Micro ATX boards still use ATX power
supplies and ATX cases.
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HANDOUT – Motherboard Form Factors Objective
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Variations on the ATX Form Factor
In 2006, Intel introduced the BTX (Balanced
Technology Extended) which was a low-profile board
with improved thermal or heat regulation. To allow
for better air flow, the backside connectors and the
expansion slots were switched. These boards are also
available in microBTX and picoBTX and have been
used by Gateway and HP.
NLX is another
motherboard
form factor
developed by Intel. NLX mobos were developed for the big
PC companies like Dell, IBM and HP to allow for smaller,
slimmer cases. The most notable feature of the NLX board
is the use of the riser card, also known as a daughterboard.
This is a smaller board that plugs into the motherboard in a
perpendicular fashion. The riser card is used to install
expansion cards while maintaining the slim system case
size.
Proprietary Form Factors
Large computer manufacturers like Dell, HP, IBM often make changes to motherboard form
factors. These boards tend to have small changes to connector types and component location.
The reason for this is so that if a technician needs to service one of these MBs or needs parts,
they have to purchase these items from the manufacturer.
What does Form Factor mean to you?
A PC technician must be aware of motherboard form factors when looking to buy or replace a
motherboard. The case and power supply form factors must match the motherboard form
factor. Therefore, if you are using an ATX motherboard, then you would want an ATX system
case and an ATX power supply.
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