Expansion cards

3.5 Given a scenario, install and configure motherboards, central processing units (CPUs), and add-on cards.

📘CompTIA A+ Core 1 (220-1201)


What Are Expansion Cards?

Expansion cards are hardware components that are installed into expansion slots on a motherboard to add or improve computer functionality.

They are also called add-on cards.

Most expansion cards connect to the motherboard using:

  • PCI Express (PCIe) slots
    (PCIe x1, x4, x8, x16)

For the A+ exam, PCIe is the most important expansion interface to remember.


Common Exam Points About Expansion Cards

You must understand:

  • What each card does
  • Which PCIe slot it uses
  • Why a system might need it
  • Basic installation and configuration
  • Common troubleshooting issues

1. Sound Card

What Is a Sound Card?

A sound card is an expansion card that:

  • Processes audio input and output
  • Converts digital audio data into sound
  • Converts sound (voice, microphone input) into digital data

Many motherboards already have onboard audio, but a separate sound card may be used for better quality or additional features.


Functions of a Sound Card

  • Plays audio through speakers or headphones
  • Records audio from microphones or audio devices
  • Supports multiple audio channels (stereo, surround sound)
  • Handles audio processing instead of the CPU

Common Ports on a Sound Card

  • 3.5 mm audio jacks
    • Line out (speakers/headphones)
    • Mic in (microphone)
    • Line in (external audio source)
  • Optical (TOSLINK) – digital audio output (higher quality)

Interface Used

  • PCIe x1 (most common for sound cards)

IT Environment Uses

  • Workstations that require high-quality audio recording
  • Systems used for training videos
  • PCs used for voice communication or audio editing

Exam Tips – Sound Card

✔ Onboard audio can be disabled in BIOS/UEFI if installing a sound card
✔ Requires device drivers from the manufacturer
✔ Check audio settings in the operating system after installation


2. Video Card (Graphics Card / GPU)

What Is a Video Card?

A video card is an expansion card that:

  • Processes and renders graphics and video output
  • Sends visual data to monitors
  • Offloads graphics work from the CPU

Video cards are also called:

  • Graphics cards
  • GPUs (Graphics Processing Units)

Functions of a Video Card

  • Displays images, video, and text
  • Handles high-resolution and multi-monitor output
  • Accelerates video playback and graphics processing

Common Ports on a Video Card

  • HDMI
  • DisplayPort
  • DVI
  • VGA (legacy, less common)

A+ exam expects you to recognize these ports.


Interface Used

  • PCIe x16 (standard for video cards)

Power Requirements

  • Many video cards require additional power from the PSU:
    • 6-pin or 8-pin PCIe power connectors
  • Systems must have:
    • A sufficient power supply
    • Adequate cooling

IT Environment Uses

  • Systems with multiple monitors
  • Workstations handling high-resolution displays
  • Computers used for video playback and editing

Exam Tips – Video Card

✔ Plug the monitor into the video card, not the motherboard
✔ Install correct GPU drivers
✔ Ensure the PSU wattage supports the card
✔ Onboard graphics may be disabled automatically when a GPU is installed


3. Capture Card

What Is a Capture Card?

A capture card is an expansion card that:

  • Captures video and audio input
  • Converts external video signals into digital data
  • Allows video to be recorded or streamed on a computer

Functions of a Capture Card

  • Records video from external sources
  • Converts analog or digital video into usable files
  • Enables live video streaming

Common Input Ports

  • HDMI
  • SDI
  • Component or composite (older devices)

Interface Used

  • PCIe x1 or PCIe x4
  • Some capture cards also exist as USB devices (but PCIe is common for internal cards)

IT Environment Uses

  • Recording training sessions
  • Capturing video from external devices
  • Streaming or archiving video content for organizations

Exam Tips – Capture Card

✔ Requires compatible recording software
✔ Needs proper drivers
✔ Check supported input resolutions and formats


4. Network Interface Card (NIC)

What Is a Network Interface Card?

A Network Interface Card (NIC) allows a computer to:

  • Connect to a network
  • Send and receive data packets

Most motherboards include onboard NICs, but expansion NICs are used when:

  • Higher speed is needed
  • Onboard NIC fails
  • Additional network ports are required

Types of NICs

  • Wired NIC
    • Uses Ethernet cable
  • Wireless NIC
    • Uses Wi-Fi (802.11 standards)

Common Ports and Features

  • RJ-45 Ethernet port (wired)
  • Antennas (wireless NICs)
  • LED indicators for:
    • Link status
    • Activity

Interface Used

  • PCIe x1 (most common)

Network Speeds (Exam Relevant)

  • 10/100 Mbps
  • 1 Gbps (Gigabit Ethernet) – very common
  • 2.5 Gbps and higher (newer NICs)

IT Environment Uses

  • Connecting PCs to local area networks (LANs)
  • Providing network access in office systems
  • Adding Wi-Fi capability to desktops

Exam Tips – NIC

✔ MAC address uniquely identifies the NIC
✔ Drivers are required for OS recognition
✔ Link lights help troubleshoot connectivity issues
✔ Onboard NIC can be disabled in BIOS/UEFI


General Installation Steps (Exam Friendly)

  1. Power off the system
  2. Unplug all cables
  3. Insert the expansion card into the correct PCIe slot
  4. Secure the card with a screw
  5. Connect power cables (if required)
  6. Boot the system
  7. Install drivers
  8. Verify functionality in the OS

Common Expansion Card Troubleshooting

  • Device not detected → Check BIOS/UEFI and drivers
  • No output → Check cables and correct port usage
  • Poor performance → Update drivers
  • System not powering on → Check PSU capacity

Key Exam Summary

✔ Expansion cards extend system functionality
✔ PCIe is the primary expansion interface
✔ Video cards use PCIe x16
✔ Sound, NIC, and capture cards usually use PCIe x1
✔ Drivers are required for all expansion cards
✔ BIOS/UEFI may need configuration changes

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