IT FundamentalsA+

Expansion Cards for CompTIA A+ 220-1101

Expansion cards add capabilities to a desktop computer through PCIe or legacy slots. CompTIA A+ 220-1101 tests the types of expansion cards — GPU, NIC, sound card, capture card — their installation, and troubleshooting. Understanding expansion cards allows technicians to upgrade systems, resolve driver conflicts, and diagnose slot or card failures.

6 min

2 sections · 7 exam key points

1 practice questions

Types of Expansion Cards

GPU (Graphics Processing Unit / Video card): the most common and significant expansion card. Plugs into PCIe x16 slot. Provides dedicated video memory (VRAM) and processing for 3D graphics, gaming, AI/ML workloads, and video editing. Requires: PCIe x16 slot, PCIe power connectors (6-pin or 8-pin from PSU), adequate PSU wattage. Driver: manufacturer driver (NVIDIA or AMD) required for full functionality — Windows loads generic driver at first install.

NIC (Network Interface Card): adds wired Ethernet port(s) to a system, or replaces a failed onboard NIC. PCIe x1 for standard Gigabit/2.5 GbE/10 GbE cards. Also: Wi-Fi cards — PCIe with external antenna connectors. PCIe Wi-Fi cards add Wi-Fi and often Bluetooth to a desktop that lacks it.

Sound card: adds or improves audio output — provides better DAC (Digital-to-Analog Converter) quality than onboard audio. Used by audio professionals and gamers. Internal PCIe sound cards or external USB audio interfaces (often called 'DACs'). Most modern systems have adequate onboard audio; dedicated sound cards are for specific quality requirements.

Capture card: records or streams video from external sources (game console, camera, another PC) — used for streaming and content creation. PCIe internal or USB external. Receives HDMI input and digitizes for recording/streaming.

Storage controller cards: add SATA ports, M.2 slots, or U.2 connections to systems lacking sufficient built-in ports. RAID controller cards: manage hardware RAID arrays independently of the CPU.

Installation and Troubleshooting

Installation process: power off and unplug. Anti-static precautions. Remove slot cover bracket. Align card with slot (PCIe x16 card in x16 slot, x1 card in x1 or larger slot). Press firmly until the retention clip clicks. Secure with bracket screw. Connect PCIe power connectors if required (GPU). Close case. Power on. Install drivers. Verify in Device Manager.

PCIe slot compatibility: a PCIe x1 card physically fits in an x4, x8, or x16 slot — the connector is the same, just shorter. A PCIe x16 card cannot fit in an x1 slot — the card is longer than the slot. Backward and forward compatible between PCIe generations (PCIe 4.0 card in PCIe 3.0 slot) — runs at the lower generation's speed.

Common issues: card not detected — reseat the card firmly, check PCIe slot with another card, check Device Manager for yellow warning. GPU performance issues — check if drivers are installed (generic Microsoft display driver vs manufacturer driver), verify PCIe power connectors connected. Driver conflict: uninstall old driver completely (DDU — Display Driver Uninstaller) before installing new GPU driver when switching GPU brands.

Key exam facts — A+

PCIe x16 slot: for GPU; x1: for NIC, sound card, small cards
PCIe x1 card fits in x4/x8/x16 slot; x16 card does not fit in x1 slot
PCIe is backward/forward compatible — runs at lowest common generation speed
GPU requires: PCIe x16 slot, PCIe power connectors, adequate PSU wattage
Install GPU driver from NVIDIA/AMD — Windows generic driver lacks performance features
DDU (Display Driver Uninstaller): fully removes GPU driver before switching brands
Capture card: digitizes HDMI input for streaming/recording — PCIe or USB external

Common exam traps

Expansion cards work immediately after being physically installed

Most expansion cards require manufacturer drivers for full functionality. Windows may load a generic class driver that provides basic operation (a new GPU may display video with Microsoft Basic Display Adapter driver) but lacks performance features, overclocking support, and settings. Always install the manufacturer's driver after physically seating the card

Practice questions — Expansion Cards

These questions are representative of what you will see on A+ exams. The correct answer and explanation are shown immediately below each question.

Q1.A technician replaces an old NVIDIA GPU with a new AMD GPU in a desktop. After installation, the display shows a low resolution and the Device Manager shows a yellow warning on the display adapter. What should be done first?

A.Replace the PCIe slot

B.Fully uninstall the NVIDIA driver using DDU, then install the AMD driver

C.Update Windows

D.Reinstall the NVIDIA GPU

Explanation: When switching GPU brands (NVIDIA to AMD), driver conflicts are common — remnants of the old NVIDIA driver can conflict with the new AMD driver. The proper procedure is: boot in safe mode, use Display Driver Uninstaller (DDU) to completely remove all GPU drivers, restart, then install the AMD driver. Without DDU, partially removed NVIDIA drivers can cause the Device Manager warning and prevent the AMD GPU from functioning correctly.

Frequently asked questions — Expansion Cards

Can a PCIe x16 GPU run in a PCIe x8 slot?

Yes — PCIe is backward compatible. A GPU designed for a PCIe x16 slot will physically fit and function in an x8 slot (the card is the same physical length; the slot uses only half the lanes). The GPU will run at PCIe x8 bandwidth instead of x16. For most modern GPUs and gaming workloads, the difference between x16 and x8 is less than 5% performance impact — often imperceptible. This matters when using multiple GPUs (SLI/CrossFire) where both cards share the available PCIe lanes.

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