3.5 Motherboard Form Factors/Compatability

ATX = ?

• Motherboard form factor

• ATX = Advanced Technology Extended

• Standardized by Intel in 1995; updated over time

• Power connectors: originally 20-pin, now 24-pin + 4/8-pin for CPU

What is microATX and its key features?

• Smaller than ATX → fewer expansion slots

• Backward compatible → similar mounting points & power connectors

• Very popular → many options available

What is Mini-ITX and its key features?

• ITX = Information Technology Extended

• Small, low-power boards → developed by VIA in 2001

• Screw-compatible with ATX → fits most cases

• Ideal for single-purpose computing (e.g., media streaming)

Expansion slots / PCI = ?

Add capabilities → PCI = old 32/64-bit parallel bus, PCIe = modern replacement

What is PCI Express (PCIe) and how does it differ from PCI?

• PCIe = modern replacement for PCI

• Communicates serially → unidirectional lanes

  • Slower devices don’t slow others

• Lane counts: x1, x2, x4, x8, x16, x32 (pronounced “by 1,” “by 16”)

• Full-duplex lanes → simultaneous send & receive

24-pin power = ?

Main motherboard power → 20-pin original, 24-pin for PCIe

What are PCIe 6-pin and 8-pin power connectors for?

• Provide extra +12 V power for high-power PCIe devices (e.g., GPUs)

• 6-pin = 75 W, 8-pin = 150 W

• Some cables split: 6 + 2 = 8-pin → fits both connectors

What is a motherboard header?

• Pin-based electrical interface on the motherboard

• Used to connect internal components

• Power connections

• Peripherals (USB, audio)

• Lights (LEDs)

• Buttons

What are front panel connectors?

• Connect the computer case to the motherboard

• Link buttons and indicator lights

• Power button

• Reset button

• Power LED

• Drive activity LED

What should you know about Intel vs AMD compatibility?

• Two main CPU manufacturers: Intel & AMD

• CPUs require specific motherboard sockets

• Not interchangeable between brands

How do Intel and AMD generally compare?

• AMD → often better value (cheaper)

• Intel → often performance-focused

• Roles can switch over time

What are the key features of a server motherboard?

• Multi-socket support → multiple CPUs

• Handles heavy workloads (split processing)

• Supports many RAM modules

How do server motherboards differ from standard motherboards?

• More expansion slots (various sizes)

• Larger size → often rack-mounted systems

• Built for scalability and performance