Computer Hardware
Week of 2026-09-01 · Download .docx
Objectives
- Compare CPU specifications — clock speed, core count, and cache — and explain how Hyper-Threading and TDP affect CPU selection.
- Distinguish volatile RAM from non-volatile storage and explain DDR generations, SO-DIMM vs. DIMM, and dual-channel memory.
- Compare HDD, SATA SSD, and NVMe SSD storage technologies and explain RAID 0, 1, and 5 configurations.
- Identify common I/O ports and connectors — USB, HDMI, DisplayPort, Thunderbolt — and explain PoE.
Key terms
- Clock Speed
- The number of instruction cycles a CPU can execute per second, measured in GHz (gigahertz, billions of cycles per second).
- Core Count
- The number of independent processing units on a single CPU die. More cores allow simultaneous execution of multiple threads.
- Hyper-Threading
- Intel's SMT (Simultaneous Multi-Threading) technology that allows each physical core to run two hardware threads, doubling the OS's logical processor count.
- TDP
- Thermal Design Power — the maximum sustained heat (watts) a CPU generates, determining minimum cooling requirements.
- DDR
- Double Data Rate — DRAM that transfers data on both edges of each clock cycle. DDR5 is the current desktop standard.
- Dual-Channel
- Memory configuration where two matched RAM sticks activate two 64-bit data paths simultaneously for 128-bit total bandwidth.
- NVMe
- Non-Volatile Memory Express — storage protocol over PCIe lanes, bypassing the SATA controller for 5–10× faster speeds than SATA SSDs.
- RAID 1
- Disk mirroring — identical data written to two drives simultaneously. One drive can fail with no data loss; capacity is 50% of total drives.
- RAID 5
- Striping with distributed parity across three or more drives. Tolerates one drive failure; better capacity efficiency than RAID 1.
- PoE
- Power over Ethernet — delivers electrical power alongside data over standard Cat5e/Cat6 cable, eliminating separate power outlets near IP cameras and WAPs.
- USB-C
- Reversible USB connector supporting multiple protocols (USB 3.x, Thunderbolt, DisplayPort, USB Power Delivery) over a single small connector.
- Thunderbolt 4
- Intel multi-protocol connector (physical USB-C) supporting 40 Gbps data, DisplayPort video, and power delivery simultaneously.
- SATA III
- Serial ATA interface with 6 Gbps maximum bandwidth (~600 MB/s effective), used for 2.5" and 3.5" SSDs and HDDs.
The concept
Computer hardware is the physical foundation on which all software runs. Understanding components, their specifications, and their interactions allows an IT professional to build, troubleshoot, and upgrade systems effectively.
**The CPU: Brain of the Computer**
The Central Processing Unit (CPU) is the component that executes all program instructions. It repeats the fetch-decode-execute cycle billions of times per second. Three specifications most directly predict CPU performance: clock speed (GHz), core count, and cache size.
Clock speed measures cycles per second on each core. A 4.5 GHz CPU completes 4.5 billion cycles per second per core. Core count determines how many tasks can be executed in parallel — a 12-core CPU can run 12 independent instruction streams simultaneously. L1/L2/L3 cache is on-chip, ultra-fast memory that stores frequently accessed instructions and data, reducing the slower RAM access penalty.
Hyper-Threading (Intel) and Simultaneous Multi-Threading (AMD) allow each physical core to present two logical processors to the OS by duplicating certain execution resources. A 6-core/12-thread CPU appears to the operating system as 12 processors.
TDP (Thermal Design Power) measures maximum sustained heat output in watts. A 125W TDP CPU needs a more capable cooling solution than a 65W model. Exceeding the TDP causes the CPU to throttle (reduce clock speed) to protect itself.
**Memory and Storage**
RAM (Random Access Memory) is volatile — it holds data only while powered. DDR (Double Data Rate) RAM transfers data on both edges of each clock cycle, effectively doubling throughput. Matching RAM sticks in paired slots activates dual-channel mode, doubling memory bandwidth by using two 64-bit data paths simultaneously.
Storage is non-volatile. HDDs store data magnetically on spinning platters read by moving actuator arms — relatively slow (~150 MB/s) and vulnerable to physical shock. SATA SSDs use NAND flash but are limited to ~550 MB/s by the SATA III interface. NVMe SSDs connect directly via PCIe lanes, reaching 3,500–7,000+ MB/s by bypassing the SATA controller entirely.
**RAID: Combining Multiple Drives**
RAID (Redundant Array of Independent Disks) configurations combine physical drives for performance, redundancy, or both. RAID 0 stripes data across drives for doubled performance but zero redundancy. RAID 1 mirrors identical data to two drives — one can fail with no loss. RAID 5 distributes parity across three drives, tolerating one failure while maintaining good capacity efficiency.
**Connectivity**
Modern systems connect peripherals through standardized interfaces. USB-C's reversible connector supports USB 3.x (up to 40 Gbps), Thunderbolt 4 (40 Gbps), DisplayPort video, and USB Power Delivery (up to 240W) — all over the same physical connector. HDMI carries digital audio and video. DisplayPort supports higher refresh rates and daisy-chaining. PoE (Power over Ethernet) delivers both data and power over standard Ethernet cable, essential for deploying IP cameras and wireless access points without running separate power cables.
Worked examples
Common mistakes
- Confusing GHz (clock speed) with performance. A newer processor at 3.5 GHz often outperforms an older 4.0 GHz chip because architecture improvements (IPC — Instructions Per Cycle) matter more than raw clock speed alone.
- Assuming M.2 means NVMe. M.2 is a physical slot that supports both SATA and NVMe SSDs. An M.2 SATA SSD is still limited to 550 MB/s. Check the spec sheet or use 'M-key' vs 'B+M-key' to determine protocol.
- Forgetting that RAID is not backup. RAID 1 protects against drive failure but not accidental deletion, ransomware, or site disasters. The 3-2-1 backup rule must be applied separately from RAID.
- Believing dual-channel requires identical capacity. While matched capacity is ideal, dual-channel activates as long as sticks are in the correct paired color-coded slots on the motherboard.
- Overlooking TDP when selecting a cooler. A stock cooler rated for 65W TDP will throttle a 125W processor. Always verify the cooler's rated TDP matches or exceeds the CPU's TDP.
Self-check
Try each question before reading the answer. Answers at the bottom of this page.
1. Which storage interface offers the fastest sequential read speeds on modern systems?
- SATA III
- USB 3.0
- NVMe PCIe
- HDD RAID 0
2. What does TDP measure?
- Transfer rate
- Maximum heat output in watts
- Threading performance
- Total disk partitions
3. Dual-channel memory mode is activated by:
- Installing two drives in RAID 1
- Placing matched sticks in paired color-coded slots
- Using DDR5 instead of DDR4
- Enabling Hyper-Threading in BIOS
4. Which RAID level provides fault tolerance without parity, using a minimum of two drives?
- RAID 0
- RAID 1
- RAID 5
- RAID 10
5. PoE is used primarily to:
- Speed up Ethernet to 10 Gbps
- Deliver power and data over a single Ethernet cable
- Connect USB-C devices to RJ45 ports
- Enable wireless 802.11ax
Self-check answers
- 1. C — NVMe PCIe bypasses the SATA controller, reaching 3,500–7,000+ MB/s versus SATA's 550 MB/s ceiling.
- 2. B — TDP (Thermal Design Power) measures maximum sustained heat in watts, determining minimum cooling requirements.
- 3. B — Matched RAM sticks in the correct paired slots double memory bandwidth by activating two 64-bit data paths.
- 4. B — RAID 1 mirrors data identically on two drives — one drive can fail with no data loss.
- 5. B — PoE (Power over Ethernet) delivers electrical power alongside data over Cat5e/Cat6, eliminating separate power outlets near cameras and WAPs.
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