Hardware Basics
What Is Hardware?
Section titled “What Is Hardware?”Hardware is the physical components that make up a computer - everything you can pick up and hold. Hardware works in concert with software, which provides the instructions the hardware executes.
Core Components
Section titled “Core Components”CPU - Central Processing Unit
Section titled “CPU - Central Processing Unit”The CPU is the brain of the computer. It performs all calculations and data processing.
- Stores active computations in registers - tiny, ultra-fast storage built into the processor
- Data flows to/from the CPU over the External Data Bus (EDB) and Address Bus
- Has 3 cache levels: L1 (smallest & fastest), L2, L3 - graduated speed/size trade-offs
- Clock speed defines the max clock cycles per second - higher = more instructions per second
RAM - Random Access Memory
Section titled “RAM - Random Access Memory”RAM is the computer’s short-term memory. It holds data for currently running programs.
- Volatile - all data is wiped when power is lost
- Common types: DRAM (Dynamic RAM) → modern variant is DDR SDRAM (Double Data Rate)
- Physical form factor: DIMM sticks (Dual Inline Memory Module)
Storage - Hard Drives & SSDs
Section titled “Storage - Hard Drives & SSDs”Holds all persistent data - operating system, applications, files.
| Type | Mechanism | Speed | Notes |
|---|---|---|---|
| HDD (Hard Disk Drive) | Spinning magnetic platters, high RPMs | Slower | Cheaper per GB |
| SSD (Solid State Drive) | Non-volatile flash chips, no moving parts | Faster | Smaller form factor |
Motherboard
Section titled “Motherboard”The motherboard is the main circuit board that connects all components together. When selecting a CPU, it must be compatible with the motherboard’s socket type.
- Contains expansion slots - PCIe slots for GPUs, network cards, etc.
- Houses the CMOS chip which stores BIOS/UEFI settings
Power Supply
Section titled “Power Supply”Converts AC power from the wall into DC power for components.
- Most basic desktops run on a 500W power supply
- Wattage = volts × amps - match it to your component requirements
- Caution: Never mismatch voltage - plugging a 220V appliance into 120V can cause damage
Peripherals & External Connections
Section titled “Peripherals & External Connections”Peripherals are external devices that add functionality - mouse, keyboard, monitor, webcam.
USB Standards
Section titled “USB Standards”| Version | Transfer Speed |
|---|---|
| USB 2.0 | 480 Mb/s |
| USB 3.0 | 5 Gb/s |
| USB 3.1 | 10 Gb/s |
SoC - System on a Chip
Section titled “SoC - System on a Chip”A SoC packs the CPU, RAM, and sometimes storage onto a single chip. Common in mobile devices, Chromebooks, and embedded systems. Trade-off: performance-limited but power-efficient.
Boot Hardware
Section titled “Boot Hardware”BIOS / UEFI
Section titled “BIOS / UEFI”BIOS (Basic Input/Output System) and its modern replacement UEFI are low-level firmware stored on the motherboard that:
- Run a POST (Power-On Self-Test) to check hardware on boot
- Initialize all connected hardware
- Hand off control to the bootloader
BIOS settings are stored on the CMOS chip and persist across reboots.
| BIOS | UEFI | |
|---|---|---|
| Disk size support | Up to 2 TB | 9.4 ZB (GPT) |
| UI | Text-only | Graphical possible |
| Boot security | None | Secure Boot |
| Standard | Legacy | Modern default |
ROM vs RAM
Section titled “ROM vs RAM”- ROM (Read-Only Memory): Non-volatile, stores permanent firmware (e.g., BIOS chip)
- RAM: Volatile, stores temporary working data
Assembly Best Practices
Section titled “Assembly Best Practices”When working on physical hardware:
- Ground yourself - prevent electrostatic discharge (ESD) that can destroy components
- Use the right tools - wrong screwdrivers strip standoffs
- Label and photograph parts before disassembly
- Follow vendor documentation
- Apply thermal paste between CPU and heat sink for effective heat transfer
- Test the system after assembly before closing the case