JH

Lecture 1.2 – Motherboards, Processors, Memory & Power

  • Motherboard: The main circuit board housing the CPU, memory, and expansion slots, establishing communication between components.

  • Processor (CPU): The central processing unit, often referred to as the brain of the computer, performing calculations and executing instructions.

  • Memory (RAM): Temporary storage allowing for quick access to data and applications currently in use, essential for smooth operation.

  • Power Supply: Converts electricity from an outlet into usable power for the computer's internal components, ensuring proper voltage and current.

Overarching Learning Goals

  • Recognize & name common computer parts/peripherals

  • Understand firmware start-up flow (BIOS → POST → OS)

  • Match CPUs with sockets, analyze specs (clock, cores, TDP, cache)

  • Classify memory types, channels & packaging

  • Appreciate heat as “enemy of performance” and choose appropriate cooling

  • Estimate/size power supplies for desktop & laptop builds

Firmware & Boot Chain

BIOS (Basic Input Output System)

  • Legacy text-based firmware stored on motherboard chip

  • FIRST code that runs after power button; initialises hardware, executes POST then hands control to OS

  • User enters BIOS via hot-key (Del, F2, etc.) to tweak low-level settings (e.g., disable USB ports)

UEFI (Unified Extensible Firmware Interface)

  • Modern BIOS replacement; GUI driven; 64-bit; larger volumes (>2 TB)

  • Security features:

    • Secure Boot – validates bootloader signatures

    • Built-in encryption hooks (TPM, HSM)

POST (Power-On Self Test)

  • Diagnostic sequence ➜ checks CPU, RAM, GPU

  • Failure indicated by beep codes/LEDs; each motherboard has chart

    • e.g., 2 short beeps = parity error, 1 long + 2 short = video error

Security Silicon

  • TPM (Trusted Platform Module): micro-controller storing crypto keys for BitLocker, Secure Boot, etc.

  • HSM (Hardware Security Module): enterprise-grade “digital vault” safeguarding certificates/keys for apps/databases

CMOS & RTC Battery

  • CMOS = Complementary Metal-Oxide Semiconductor memory (stores BIOS settings & system clock)

  • Coin-cell battery (CR2032) supplies power when PC unplugged

  • Symptoms of failure → wrong date/time at boot; simple “pop-out/pop-in” replacement

CPU Fundamentals

The “Brain”; motherboard = “Nervous System”

Architectures

  • x86/x64 – CISC instruction sets by Intel/AMD (32-bit vs 64-bit)

  • ARM (Advanced RISC Machine) – RISC; ultra-low-power phones/tablets/Apple Silicon servers

Physical Socket Families

  • AMD AM4, AM5, sWRX8 (Threadripper)

  • Intel LGA 1200, 1700, etc.

Key Characteristics

  • Cores = independent execution units (dual, quad, octa, 64-core Threadripper)

  • Threads / SMT / Hyper-Threading (Intel) = 1 core presents 2 logical processors

  • Clock Speed – GHz; many CPUs list Max Turbo Frequency

  • Cache – L1/L2/L3 ; faster than RAM

  • TDP (Thermal Design Power) – watts of heat to dissipate

  • Virtualisation Extensions – Intel VT-x, AMD-V enable hardware VMs

Memory Essentials

  • Purpose: hold active code/data for CPU (volatile)

Error Detection

  • Parity (odd/even bit) – detects but can’t correct

  • ECC – detects & self-corrects single-bit errors; mission-critical servers, DBs

Module Layout

  • Single- vs Double-sided (chips on 1 or 2 faces)

  • Channel configs: Single, Dual, Triple, Quad ➜ matched sticks maximise bandwidth (install in slots A2 + B2 first)

Technology Timeline

Generation

Bus Actions/Clock

Voltage

Notes

DRAM / SDR

1 transfer

3.3 V

Legacy (FPM, EDO, BEDO)

DDR-SDRAM 1

2 transfers

2.5 V

DDR2

2 × prefetch

1.8 V

DDR3

8 × prefetch

1.5 V

DDR4

faster, 1.2 V

DDR5

> 6400 MT/s, 1.1 V

  • SRAM – static, costly, CPU cache

  • ROM – non-volatile firmware storage

Form Factors

  • DIMM (Desktop) 168/240/288-pin

  • SO-DIMM (Laptop, NUC) 204/260-pin

Cooling & Thermal Management

  • P_{heat}=TDP ➜ remove via airflow or liquid

Solutions

  • Case Fans (intake + exhaust); orientation matters

  • CPU Air Cooler = heat-sink + fan + thermal paste (pea-sized drop, NOT on pins!)

  • Liquid / AIO: pump, tubing, radiator; efficient for multi-GPU mining rigs

  • Component-specific: RAM heat-spreaders, VRM sinks, HDD bay fans

Power Supply (PSU / Laptop Brick)

  • Converts AC{wall}\rightarrow DC{12/5/3.3} (formula P=V\times I)

  • Select wattage ≥ calculated load; system only draws what it needs ➜ overspec = safe

  • Desktop rating printed on PSU label; laptop rating on AC adapter (65 W, 90 W, 130 W…)

Hands-On Exercise Highlights

  1. Built CPU spec table via AMD & Intel product pages

    • Examples collected:
      • AMD Ryzen Threadripper 5995WX — sWRX8, up to 4.5 GHz, TDP=280\,W, 64 cores, 256 MB L3
      • Ryzen 9 7950X — AM5, 5.7 GHz, TDP=170\,W, 16 cores
      • Intel Core i5-11400F — LGA 1200, 4.4 GHz Turbo, TDP=65\,W, 6 cores
      • Intel Core i9-14900K — LGA 1700, 6 GHz Turbo, P_{max}=253\,W, 24 cores

  2. Chose two recent CPUs, compared speed, cache, core-count & gaming suitability

  3. Located existing PSU / laptop brick wattage; estimated component draw via lookup table

  4. Shopped online (Amazon screenshot) for adequate replacement (e.g., 65 W USB-C adapter)

Practice-Quiz Q&A Recap

  • PSU converts electricity, not store files

  • CPU installs in motherboard socket

  • RAM = Random Access Memory in DIMM slot

  • Signs of bad PSU: random shutdown/no power

  • Thermal paste + heat-sink prevent CPU overheating

  • Motherboard = central hub

Practical Lab Tips

  • POST beep charts handy during troubleshooting

  • PXE (Pre-eXecution Environment) configured in BIOS “Boot Options” for network imaging

  • Handle CPUs/RAM gently; bent LGA pins or uneven DIMM pressure = dead system

  • Apply one pea-sized blob of thermal paste; clamp cooler evenly

Study & Exam Strategy

  • Master acronym list (BIOS, UEFI, TPM, ECC, TDP, DIMM, etc.)

  • Use lots of timed practice tests; skip & return to tricky items

  • Connect concepts to real-world (e.g., sizing PSUs for judge-chamber PC rollouts, enabling BitLocker TPM)

Class Session Context

  • Week 1, Night 2 of CIS-101A-21 (July 14 term)

  • 50 min lecture / 10 min break rhythm (06:50, 07:50, 08:50)

  • Attendance/roll-call, recap of previous night (intro to hardware)

  • Continuation topic: Motherboards, Processors & Memory + hands-on CPU/PSU exercise

Overarching Learning Goals

  • Recognise & name common computer parts/peripherals

  • Understand firmware start-up flow (BIOS → POST → OS)

  • Match CPUs with sockets, analyse specs (clock, cores, TDP, cache)

  • Classify memory types, channels & packaging

  • Appreciate heat as “enemy of performance” and choose appropriate cooling

  • Estimate/size power supplies for desktop & laptop builds

Firmware & Boot Chain

BIOS (Basic Input Output System)

  • Legacy text-based firmware stored on a non-volatile chip (ROM or EEPROM) on the motherboard. It's often considered legacy due to its limited features and 16-bit architecture.

  • FIRST code that runs immediately after the power button is pressed; it performs initial hardware setup (like recognising drives, USB devices, and graphics cards), executes the POST, and then hands control to the operating system's bootloader.

  • Users can enter the BIOS setup utility via specific hot-keys (commonly Del, F2, F10, F12, or Esc) during system startup to tweak low-level settings such as boot order (e.g., from HDD, USB, or Network), modify system date/time, disable integrated peripherals (e.g., disable USB ports, integrated audio), or set system passwords.

UEFI (Unified Extensible Firmware Interface)

  • Modern replacement for BIOS, offering significant advancements:

    • GUI-driven interface: Provides a more user-friendly graphical interface, often with mouse support, compared to the text-based BIOS.

    • 64-bit support: Allows for a more direct and efficient boot process for 64-bit operating systems.

    • Supports larger volumes: Can boot from drives larger than 2 TB, which was a limitation for traditional BIOS.

    • Enhanced security features:

    • Secure Boot: A critical feature that validates the digital signatures of bootloaders and operating system components to ensure they haven't been tampered with by malware. If a signature is invalid, the system won't boot.

    • Built-in encryption hooks: Integrates with hardware encryption technologies like TPM and HSM for disk encryption (e.g., BitLocker) and secure key storage.

POST (Power-On Self Test)

  • A crucial diagnostic sequence initiated by the BIOS/UEFI firmware immediately after power-on.

  • It methodically checks essential hardware components including the CPU, RAM, GPU, keyboard, and other critical system devices to ensure they are present and functioning correctly.

  • Failure indication: If a hardware component fails the POST, the system typically indicates the error through distinct methods:

    • Beep codes: A series of audible beeps (e.g., 2 short, 1 long + 2 short) emitted by the motherboard speaker. Each motherboard manufacturer has a unique chart mapping these codes to specific hardware failures (e.g., 2 short beeps often signify a parity error in RAM, while 1 long + 2 short typically indicates a video error).

    • LEDs: Many modern motherboards include diagnostic LEDs that illuminate or display codes to pinpoint the problematic component.

  • A successful POST typically results in a single short beep, confirming that basic hardware is operational, and control is then passed to the bootloader.

Security Silicon

  • TPM (Trusted Platform Module): A dedicated, tamper-resistant micro-controller chip (often a small black chip on the motherboard) that stores cryptographic keys and performs cryptographic operations in a secure environment. It is essential for features like BitLocker drive encryption, Secure Boot, and Windows Hello, ensuring the integrity of the computing platform.

  • HSM (Hardware Security Module): An enterprise-grade physical computing device that safeguards and manages digital keys for strong authentication and provides cryptoprocessing. It acts as a “digital vault” for highly sensitive cryptographic material like certificates and encryption keys used by applications and databases, offering a higher level of security and compliance for critical infrastructure.

CMOS & RTC Battery

  • CMOS (Complementary Metal-Oxide Semiconductor): Refers to a small, non-volatile memory chip on the motherboard that stores the BIOS/UEFI settings (like boot order, hardware configurations, and system passwords) and the system clock/date. It consumes very little power.

  • The coin-cell battery (CR2032) is essential because it supplies continuous power to the CMOS memory and the Real-Time Clock (RTC) chip, even when the PC is unplugged from the AC power. This ensures that the system retains its configuration and accurate time.

  • Symptoms of failure: A failing or dead CMOS battery typically results in:

    • Incorrect date/time at boot (often reverting to a default date like 2000).

    • Loss of BIOS/UEFI settings, requiring them to be reconfigured after every power cycle.

    • Boot errors or difficulty starting the operating system.

  • Replacement: It's a simple “pop-out/pop-in” replacement procedure for the CR2032 battery.

CPU Fundamentals

The “Brain”; motherboard = “Nervous System”

Architectures

  • x86/x64: These are CISC (Complex Instruction Set Computing) instruction set architectures primarily developed and used by Intel and AMD for desktop, laptop, and server processors.

    • 32-bit vs. 64-bit: x86 refers to 32-bit processors, while x64 (also known as AMD64 or Intel 64) refers to 64-bit processors, which can process more data per clock cycle and address significantly larger amounts of RAM.

  • ARM (Advanced RISC Machine): This is a RISC (Reduced Instruction Set Computing) architecture known for its high energy efficiency and performance per watt. ARM processors are dominant in ultra-low-power devices such as smartphones, tablets (e.g., Apple A-series, Qualcomm Snapdragon), and are increasingly used in laptops (Apple Silicon) and servers (e.g., AWS Graviton).

    • CISC vs. RISC: CISC architectures use complex, multi-step instructions, while RISC architectures use simpler, single-cycle instructions, often leading to better power efficiency and predictable execution.

Physical Socket Families

  • AMD: Common modern sockets include AM4 (PGA – Pin Grid Array, where pins are on the CPU) and AM5 (LGA – Land Grid Array, where pins are on the motherboard) for mainstream desktops, and sWRX8 for high-end Threadripper workstation CPUs.

  • Intel: Primarily uses LGA (Land Grid Array) sockets, where the pins are on the motherboard and the CPU has flat contact pads. Examples include LGA 1200, LGA 1700 (current generation), and previous sockets like LGA 1151.

Key Characteristics

  • Cores: These are the independent processing units within a single CPU package. Each core can execute instructions independently, allowing for true parallel processing. Modern CPUs come with varying core counts (e.g., dual-core, quad-core, octa-core, up to 64-core Threadripper and beyond), significantly improving performance for multitasking and multi-threaded applications.

  • Threads / SMT (Simultaneous Multi-threading) / Hyper-Threading (Intel): This technology allows a single physical CPU core to act as two