microATX Motherboard Interface Specification

Version 1.2

Page 6

1. Executive Summary

microATX is a motherboard form factor developed as a natural evolution of the ATX form factor to address

market trends and PC technologies. This specification defines the interface between the motherboard and the

chassis.

microATX supports:

• Current processor technologies

• The transition to newer processor technologies

• Accelerated Graphics Port (AGP) high performance graphics solutions

• Smaller motherboard size

• Smaller power supply form factor

microATX is a public specification intended for widespread use in many types of systems. The specification

and related information on microATX are available through a public Web site located at:

http://www.formfactors.org

Table 1 summarizes the features of the microATX form factor.

Table 1: microATX Feature Summary

Feature Benefit

9.6” x 9.6” (244 x 244 mm)

motherboard, maximum size

• Smaller size promotes a smaller system size.

• Smaller size reduces overall system cost.

Standard ATX 2.1 or later I/O

panel

• I/O shield does not need to be retooled.

• Motherboard could be used in an ATX 2.1-compliant chassis (with minor

modifications).

Reduced I/O slots

• Higher integration on motherboard reduces motherboard and system costs.

• A smaller power supply can be used.

Small form-factor power supplies have been defined for use with several different products, including

microATX board and chassis designs. The smaller size of these power supplies encourages flexibility in

choosing mounting locations within the chassis.

1.1 Other Technical Documents

For information about the following areas, see the series of microATX design guidelines and suggestions on

the microATX public Web site at http://www.formfactors.org:

• SFX12V Power Supply Design Guide

• TFX12V (Thin Form Factor with 12 V Connector) Power Supply Design Guide

• microATX Electrical Design Suggestions

• microATX Chassis Checklist

• microATX System Design Suggestions

• microATX EMC Design Suggestions

• microATX Thermal Design Suggestions

• Performance microATX Thermal Design Suggestions

• PCI-Express specification (see Web site: http://www.pcisig.com/specifications )