Storage Technology – Concise Review

Secondary Storage Characteristics

• Key factors to compare:

  • Capacity (how much data)

  • Speed (data access/read-write rate)

  • Portability (ease of moving device/media)

  • Durability (resistance to damage)

  • Reliability (consistency of data retention)

  • Cost (price per unit / per $GB$)

Storage Technologies Overview

• Magnetic (e.g. HDD)

  • Very high capacity, low $\text{£}/\text{GB}$

  • Moderate speed, moving parts → noise & wear

  • Low portability & durability

• Optical (e.g. CD, DVD, Blu-ray)

  • Cheap media, good for mass distribution

  • Read-only or write-once variants

  • Small capacity, slow access

  • Lightweight & reasonably durable

• Solid State (e.g. SSD, USB flash, SD card)

  • Fast access (no seek time), silent

  • Very portable, no moving parts → high durability

  • Low power consumption

  • Higher $\text{£}/\text{GB}$, lower max capacity than magnetic

Quick Selection Guide

• Need maximum capacity & fixed installation → Magnetic

• Need cheap, read-only mass distribution → Optical

• Need speed, portability, durability, low power → Solid State

Typical Scenario Matches

• Game distribution for console → Optical (portable, cheap, installs to HDD)

• File transfer home↔school → Solid State (USB flash: portable, durable, low cost)

• PC system & apps storage → Magnetic (large, reliable, speed acceptable)

• Helmet action camera → Solid State (shock-proof, small, reliable)

• Sending photos to relatives without internet → Optical disc or USB (depends on PC drive; optical highlighted for cheap mailing)

Exam Pointers

• Common 4-mark question: list any four characteristics (capacity, speed, portability, durability, reliability, cost).

• Always state technology type (Magnetic / Optical / Solid State) when justifying.

• Link reason to spec: e.g. “Solid State is fast ⇒ less delay when turning pages.”

• Remember: CD-ROM = Optical; read-only, cheap, enough for e-books, easily mailed.