Motherboard Form Factor

8/9/2019 Motherboard Form Factor

1/19

Form Factor


2/19

The shape and layout of a motherboard iscalled theform factor.

The form factor affects where individual

components go and the shape of thecomputer's case.

There are several specific form factors that

most PC motherboards use so that theycan all fit in standard cases.


3/19

Theform factordetermines the general

layout, size, and feature placement on a

motherboard.

Different form factors usually require

different style cases.

Differences between form factors can

include;

physical size and shape

mounting hole location

feature placement

power supply connectors, and others.


4/19

AT & Baby AT

Prior to 1997, IBM computers used large

motherboards. After that, however, the size of

the motherboard was reduced and boards using

theAT (AdvancedTechnology) form factor wasreleased. TheAT form factor is found in older

computers (386 class orearlier). Some of the

problems with this form factor mainly arose from

the physical size of the board, which is 12" wide,often causing the board to overlap with space

required for thedrive bays.


5/19

Following theAT form factor, theBaby AT

form factor was introduced. With the BabyAT form factor the width of themotherboard was decreased from 12" to8.5", limiting problems associated with

overlapping on the drive bays' turf. Baby AT became popular and was

designed for peripheral devices such asthekeyboard, mouse, and video to be

contained on circuit boards that wereconnected by way ofexpansion slots onthe motherboard.


6/19

Baby AT


7/19

ATX

ATXWith the need for a moreintegrated form factorwhich defined standard locations for thekeyboard, mouse, I/O, and video connectors, in

the mid 1990's theATX form factor wasintroduced. TheATX form factor brought aboutmany chances in the computer. Since theexpansion slots were put onto separaterisercards that plugged into the motherboard, theoverall size of the computer and its case wasreduced. TheATX form factor specified changesto the motherboard, along with the case andpower supply.


8/19

ATX


9/19

ATX


10/19

Micro-ATX

MicroATX followed theATX form factor and

offered the same benefits but improved the

overall system design costs through a reduction

in the physical size of the motherboard. This wasdone by reducing the number of I/O slots

supported on the board. The microATX form

factor also provided more I/O space at the rear

and reduced emissions from using integrated I/Oconnectors.


11/19

LPX Found in low-profile cases (desktop model as

opposed to a tower or mini-tower) with a risercard arrangement forexpansion cards whereexpansion boards run parallel to themotherboard.

While this allows for smaller cases it also limitsthe number ofexpansion slots available.

sound and video integrated onto themotherboard.

difficult to repair due to a lack of space andoverall non-standardization.

TheLPX form factor is not suited to upgradingand offer poor cooling.


12/19

LPX


13/19

NLX

Boards based on theNLX form factorhitthe market in the late 1990's. This"updated LPX" form factor offered support

for larger memory modules, tower cases,AGP video support and reduced cablelength. In addition, motherboards areeasier to remove. TheNLX form factor,unlikeLPX is an actual standard whichmeans there is more component optionsfor upgrading and repair


14/19

NLX


15/19


16/19


17/19


18/19


19/19

E_references:

http://home.fuse.net/Walts_Place/motherb

o.htm

http://www.viaarena.com/images/articles/pcie%20002.jpg

Documents

Motherboard Form Factor