Motherboard Sizes Guide: Best Choice for 2025

Comprehensive Guide to Motherboard Sizes: Selecting the Ideal Form Factor for Your 2025 Build

When embarking on the journey of building a custom PC, the motherboard serves as the cornerstone of your system’s architecture. Its size, known as the form factor, dictates not only the physical dimensions of your build but also its expandability, performance capabilities, and compatibility with other components. In 2025, understanding the nuances of motherboard sizes is paramount to crafting a system that aligns with your specific requirements.

Motherboard Sizes Guide

Overview of Motherboard Form Factors

The primary motherboard form factors prevalent in 2025 include:

Motherboard Sizes Guide

• Mini-ITX
• MicroATX
• ATX
• Extended ATX (E-ATX)

Each form factor offers distinct advantages and considerations, influencing your system’s overall design and functionality.

Mini-ITX: Compact Efficiency

Dimensions: 17 x 17 cm (6.7 x 6.7 inches)

Overview: Introduced by VIA Technologies in 2001, Mini-ITX motherboards are renowned for their compact footprint, making them ideal for small form factor (SFF) builds. Despite their size, they can support standard desktop processors, offering a balance between performance and space efficiency.

Key Features:

• Expansion Slots: Typically equipped with a single PCIe x16 slot, limiting expansion options.
• RAM Support: Usually supports up to two DIMM slots, accommodating dual-channel memory configurations.
• Connectivity: May have fewer USB ports and SATA connectors due to space constraints.

Ideal Use Cases:

• Home Theater PCs (HTPCs): Compact size fits seamlessly into entertainment centers.
• Portable Systems: Suitable for LAN parties or mobile workstations.
• Minimalist Desktops: For users prioritizing space-saving over extensive expandability.

(Image credit: ASRock / MSI)

Considerations:

• Limited Expansion: Restricted to one expansion slot, affecting the ability to add multiple GPUs or additional cards.
• Thermal Management: Smaller cases may present cooling challenges, necessitating efficient thermal solutions.

MicroATX: Balanced Versatility

Dimensions: Up to 24.4 x 24.4 cm (9.6 x 9.6 inches)

Overview: MicroATX motherboards offer a middle ground between compactness and expandability. They provide more features than Mini-ITX while maintaining a relatively small size, making them a popular choice for budget-conscious and mainstream users.

Key Features:

• Expansion Slots: Typically includes up to four expansion slots, supporting various configurations such as one PCIe x16 and additional PCIe x1 slots.
• RAM Support: Supports up to four DIMM slots, enabling higher memory capacities and dual-channel configurations.
• Connectivity: Offers a balanced number of USB ports, SATA connectors, and other I/O options.

Ideal Use Cases:

• General-Purpose Builds: Suitable for everyday computing tasks with moderate expandability needs.
• Budget Gaming Rigs: Allows for a dedicated GPU and additional peripherals without requiring a larger case.
• Office Computers: Provides necessary functionality for business applications within a compact form factor.

(Image credit: Asus)

Considerations:

• Moderate Expansion: While offering more slots than Mini-ITX, it still has limitations compared to larger form factors.
• Case Compatibility: Compatible with both MicroATX and larger ATX cases, providing flexibility in case selection.

ATX: Standard for Performance

Dimensions: 30.5 x 24.4 cm (12 x 9.6 inches)

Overview: ATX motherboards are the standard choice for most desktop builds, offering a comprehensive set of features, ample expansion capabilities, and widespread compatibility with cases and components.

Key Features:

• Expansion Slots: Typically provides seven expansion slots, accommodating multiple GPUs and additional expansion cards.
• RAM Support: Supports up to eight DIMM slots, facilitating high-capacity memory configurations and advanced performance setups.
• Connectivity: Rich I/O options, including numerous USB ports, SATA connectors, and often multiple M.2 slots for NVMe storage.

Ideal Use Cases:

• High-Performance Gaming: Supports multi-GPU configurations and advanced cooling solutions.
• Workstations: Ideal for professional applications requiring significant expansion and connectivity.
• Enthusiast Builds: Offers flexibility for overclocking and custom modifications.

(Image credit: Gigabyte)

Considerations:

• Larger Footprint: Requires mid-tower or full-tower cases, which occupy more physical space.
• Cost: Generally higher-priced than smaller form factors, though they offer more features and expandability.

Extended ATX (E-ATX): Ultimate Expandability

Motherboard Sizes Guide: Dimensions: Up to 30.5 x 33 cm (12 x 13 inches)

Overview: E-ATX motherboards are designed for users demanding the utmost in expansion and performance, often utilized in high-end gaming rigs and professional workstations.

Key Features:

• Expansion Slots: Offers seven or more expansion slots, with additional space for components due to the increased width.
• RAM Support: Supports up to eight DIMM slots, similar to ATX, but with more room for high-end memory configurations.
• Connectivity: Enhanced I/O options, including additional USB ports, SATA connectors, and multiple M.2 slots.

Ideal Use Cases:

• Extreme Gaming Systems: Accommodates multiple GPUs, extensive storage solutions, and advanced cooling systems.
• Professional Workstations: Suitable for tasks requiring significant computational power, such as video editing and 3D rendering.
• Server Builds: Can be used in server environments where expandability and performance are critical.

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