3.4: Motherboards, CPUs, and Add-On Cards

Motherboard form factors

Determines physical size, layout, standardized power connectors, and airflow; over 40 types exist.

ATX (Advanced Technology Extended)

Motherboard form factor standardized by Intel in 1995; uses 20 or 24-pin connectors plus optional 4/8-pin CPU power.

ITX

Small motherboard form factor created by VIA; Mini-ITX is compatible with ATX mounts; ideal for low-power or single-purpose devices.

Computer Bus

Communication system that transfers data between internal components of a computer

PCI (Peripheral Component Interconnect)

Parallel interface with 32/64-bit options; used in older systems.

PCI Express (PCIe)

High-speed serial interface with unidirectional lanes (x1, x2, x4, x16, x32); faster and more efficient than PCI.

24-pin motherboard power

Main power connector supplying +3.3V, ±5V, ±12V; 24-pin can work with 20-pin ports.

4-pin ATX power connector

Provides +12V CPU power; labeled ATX12V, P4, or CPU.

SATA connector

Connects storage drives to motherboard; some boards support eSATA via expansion card.

Header

Pin-based connector for power, buttons, lights, and peripherals on the motherboard.

Intel vs AMD

Two CPU manufacturers; different sockets; Intel generally for performance, AMD for value.

Server motherboards

Support multiple CPUs, large memory capacity, numerous expansion slots; often rack-mounted.

Desktop motherboards

Typically support one CPU, 2–4 RAM slots, and limited expansion; vary in size.

Mobile motherboards

Compact, low-power boards in laptops; limited modification and thermal throttling.

System board

Proprietary motherboard design; difficult to repair or replace due to integration of most components.

BIOS

Basic Input/Output System; firmware that initializes hardware and launches the OS.

Power-On Self-Test (POST)

Initial BIOS diagnostic test of CPU, RAM, and essential components. Will signal an error if detected. System doesn’t proceed in boot process if this test fails.

Legacy BIOS

Older firmware standard; limited modern hardware support; replaced by UEFI.

UEFI (Unified Extensible Firmware Interface) BIOS

Modern replacement for legacy BIOS with graphical interface.

BIOS Secret Buttons

Common keys: Del, F1, F2, Ctrl-S, Ctrl-Alt-S; used to enter system setup.

Fast Startup

Windows feature that skips full shutdown; use Shift + Restart to access BIOS settings.

BIOS config tips

Always back up before making changes; photograph settings as a precaution.

Boot Options

BIOS settings to enable/disable devices and configure boot priority order.

USB Permissions

BIOS setting to enable/disable USB access; used for security control.

Fan Controller

BIOS may control CPU/chassis fans based on temperature readings; helps manage heat.

Secure Boot

UEFI feature that blocks unsigned OS software during boot; protects against malware.

BIOS password

Prevents system or BIOS access without password; includes User and Supervisor levels.

Use motherboard jumper or remove CMOS battery to reset BIOS settings (including your password).

CMOS (Complementary Metal-Oxide-Semiconductor) battery

Maintains BIOS settings and system time; old systems require battery, newer use flash memory (jumper used to reset flash memory)

TPM (Trusted Platform Module)

Hardware-based encryption support with secure key storage.

HSM (Hardware Security Module)

High-end external or embedded device for key storage and cryptographic functions.

32-bit OS

Processes 32-bit data; supports up to 4GB RAM (effectively ~3.2GB); labeled x86. can't run 64-bit apps

64-bit OS

Processes 64-bit data; supports vast memory space (17+ billion GB); labeled x64. can run both 64- and 32-bit apps.

ARM

CPU architecture optimized for low power and heat; used in mobile/IoT; licensed design.

Processor cores

Can be dual/quad/or multi-core; multiple cores enable parallel processing; each core may share or have dedicated cache.

Hyper-Threading (HTT)

Intel tech allowing a single CPU core to act like two; 15–30% performance gain.

Virtualization support

Processor feature for running multiple OSes on a single hardware platform; Intel VT or AMD-V.

Expansion card

Add-on card to extend PC functionality; install card, install driver.

Sound card

Card that improves input/output audio quality; used for music, podcasting, theater sound.

Video card

Dedicated GPU card; boosts performance for gaming or video editing.

Capture card

Card that inputs video for recording or streaming; requires high bandwidth; connects via PCIe.

NIC (Network Interface Card)

Adds Ethernet capability; common on servers and routers.

Driver installation

Follow instructions; may require uninstalling old drivers; update via Device Manager.

Case fans

Pull cool air through the case; airflow design and layout affect cooling.

On-board fans

Installed on components like GPUs; help dissipate heat from high-performance cards.

Fan specs

Come in standard sizes (e.g., 80mm, 120mm, 200mm); vary in speed and noise.

Passive cooling

Uses heat sinks without fans; quiet and power-efficient for controlled environments.

Heat sink

Metal component that dissipates heat via thermal conduction and surface area.

Thermal paste

Conductive grease that improves heat transfer between chip and heat sink.

Thermal pad

Easy-to-use solid thermal interface; not reusable after removal.

Liquid cooling

Circulates coolant to manage heat; used in high-end, gaming, and overclocked systems.