PC Components Overview
PC Components Overview
Understand what every part inside a desktop PC does before you buy or build.
The Core Components
Every desktop PC is built from the same set of core components. Understanding what each one does helps you choose the right parts, diagnose faults, and plan upgrades.
CPU ߀” Central Processing Unit
The CPU is the brain of the computer. It executes instructions from programs.
- Socket: Physical connection to the motherboard (e.g. Intel LGA1700, AMD AM5)
- Cores / Threads: More cores = better multitasking. 6߀“8 cores is mainstream in 2024
- Clock speed: Measured in GHz ߀” higher is faster for single-threaded tasks
- TDP: Thermal Design Power ߀” how much heat (and cooling) the CPU requires
- Cache: L1/L2/L3 on-chip memory; larger cache improves performance
Popular lines: Intel Core i5/i7/i9, AMD Ryzen 5/7/9
RAM ߀” Random Access Memory
RAM holds data the CPU is actively using. More RAM allows more programs to run simultaneously.
- Capacity: 16 GB is the current minimum for comfortable multitasking; 32 GB for workstations
- Type: DDR4 or DDR5 (must match motherboard)
- Speed: Measured in MHz (e.g. DDR5-5600); faster RAM gives small gains in most tasks
- Slots: Motherboards have 2 or 4 DIMM slots; use matched pairs for dual-channel
GPU ߀” Graphics Processing Unit
The GPU renders images, video, and 3D graphics. Discrete GPUs have their own VRAM.
- VRAM: Dedicated video memory; 8 GB is the minimum for modern gaming
- PCIe slot: Connects to the motherboard via a PCIe x16 slot
- Integrated graphics: CPUs with an iGPU (e.g. Intel UHD, AMD Radeon) can run without a discrete GPU
- Power connectors: High-end GPUs require 6-pin or 8-pin PCIe power from the PSU
PSU ߀” Power Supply Unit
The PSU converts AC mains power to the DC voltages the PC uses (+12 V, +5 V, +3.3 V).
- Wattage: Total capacity (e.g. 650 W, 850 W). Add up all component TDPs and add 20% headroom
- 80 PLUS rating: Efficiency certification (Bronze ߆’ Gold ߆’ Platinum ߆’ Titanium)
- Modularity: Fully modular PSUs let you detach unused cables ߀” cleaner builds
- Form factor: ATX is standard; SFX is for small cases
Motherboard
The motherboard connects all components. Its chipset determines which CPUs, RAM, and features are supported.
| Feature | What it affects |
|---|---|
| Socket | Which CPUs are compatible |
| Chipset | Overclocking support, PCIe lanes, USB ports |
| RAM slots | How many DIMMs and max capacity |
| Form factor | ATX (full), Micro-ATX, Mini-ITX |
| M.2 slots | Number of NVMe SSDs supported |
Storage
| Type | Interface | Speed | Use case |
|---|---|---|---|
| HDD | SATA | ~150 MB/s | Bulk storage, backups |
| SATA SSD | SATA | ~550 MB/s | OS drive, general use |
| NVMe SSD | PCIe M.2 | 3,000߀“7,000 MB/s | OS drive, fast storage |
Case & Cooling
- Case form factor must match the motherboard form factor (ATX case fits ATX, Micro-ATX, Mini-ITX)
- CPU cooler: Stock cooler (included with CPU) or aftermarket air/liquid cooler
- Case fans: Intake at front/bottom, exhaust at rear/top for positive or negative pressure airflow
- Thermal paste: Applied between CPU and cooler to fill microscopic gaps and conduct heat