Motherboard Form Factors

Aug 21, 2025

Overview

This lecture explains the role and structure of motherboards in computers, focusing on common motherboard sizes (ATX and ITX), their features, and scenarios for their use.

Motherboard Basics

  • The motherboard is the core physical component in all computers.
  • It houses the CPU, memory slots, power connections, and expansion slots.
  • All computer operations begin and end with interactions through the motherboard.
  • Motherboards come in various sizes, affecting features and expansion capabilities.
  • Despite size differences, most motherboards use a standardized power connector for compatibility.

Importance of Motherboard Size

  • Choice of motherboard often depends on case size, desired expansion, and cooling needs.
  • Larger cases support larger motherboards with more expansion options.
  • Small form factor devices require smaller motherboards with fewer slots.

Common Motherboard Types

  • Although there are over 40 motherboard types, only two or three are widely used.
  • ATX (Advanced Technology Extended) and ITX are the two main families for desktops and small devices.
  • ATX is most common in desktops, offering many expansion and memory slots.
  • ITX (specifically Mini ITX) is suited for small form factor systems like media centers or thin clients.

ATX Motherboards

  • ATX is the standard since 1995 for desktop computers.
  • Modern ATX boards usually have a 20 or 24-pin power connector and additional CPU power connectors.
  • They offer ample expansion slots and memory capacity.

ITX Motherboards

  • Developed by VIA Technologies in 2001, ITX boards are designed for compact systems.
  • Mini ITX size allows use in small cases, ideal for tight spaces.
  • Mounting holes are compatible with ATX cases, allowing flexible installation options.

Choosing the Right Motherboard

  • Select based on the task: large ATX for desktops, Mini ITX for media centers or where space is limited.
  • Understanding motherboard size and features is necessary for matching to specific computer tasks.

Key Terms & Definitions

  • Motherboard — The main circuit board that connects all computer components.
  • ATX (Advanced Technology Extended) — A popular motherboard standard for desktops, established in 1995.
  • ITX — A family of smaller motherboards, with Mini ITX being common for compact systems.
  • Expansion Slots — Slots for adding cards like graphics or network adapters.
  • Form Factor — The physical size and shape of a motherboard.

Action Items / Next Steps

  • Review scenarios in which you would choose ATX vs. ITX motherboards.
  • Understand basic motherboard layouts and standardized connectors for the exam.