Why does a computer need secondary storage and how do you choose the right type?
The need for secondary storage, the common types (optical, magnetic, solid state) and how to choose a suitable device using capacity, speed, portability, durability, reliability and cost.
An OCR J277 1.2.2 answer on the need for secondary storage, the three common types (optical, magnetic, solid state), and how to choose a suitable device by capacity, speed, portability, durability, reliability and cost.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this dot point is asking
OCR wants you to explain why secondary storage is needed, name and describe the three types (optical, magnetic, solid state), and choose a suitable device for a scenario by weighing up six factors: capacity, speed, portability, durability, reliability and cost. The scenario question is the high-tariff one, so practise justifying a choice against several factors.
Why a computer needs secondary storage
The three types of secondary storage
Choosing a suitable device
Putting the factors together
No single type is best for everything; the right choice depends on the task. Solid state wins when speed, durability and portability matter (a laptop drive, a camera card, a USB stick). Magnetic wins when capacity and low cost matter and the drive does not move (a server, a desktop, a large backup). Optical wins when cheap, portable, read-mostly distribution matters (selling a film or game on disc), though downloads have largely replaced it. A strong answer always links the chosen type back to the specific demands of the scenario.
Try this
Q1. State why a computer needs secondary storage as well as RAM. [1 mark]
- Cue. RAM is volatile and loses data when the power is off, so secondary storage keeps data permanently.
Q2. Name the type of secondary storage that uses flash memory with no moving parts. [1 mark]
- Cue. Solid state (for example an SSD or USB flash drive).
Q3. Give two factors you would consider when choosing secondary storage for a portable device. [2 marks]
- Cue. Any two of: portability, durability, speed, capacity, cost, reliability.
Exam-style practice questions
Practice questions written in the style of OCR exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
OCR 20213 marksName the three common types of secondary storage and give one example device for each.Show worked answer →
Award one mark for each correct type paired with a valid example, up to three.
Magnetic: a hard disk drive (HDD), or a magnetic tape used for backups.
Optical: a CD, DVD or Blu-ray disc.
Solid state: a solid-state drive (SSD), a USB flash drive, or an SD/memory card.
Markers reward the correct type name with a matching example. Naming RAM or cache is wrong, because those are primary storage, not secondary storage.
OCR 20236 marksA photographer needs portable storage to carry large numbers of high-resolution photos between locations and edit them quickly on a laptop. Recommend a suitable type of secondary storage and justify your choice by referring to at least three of: capacity, speed, portability, durability, reliability and cost.Show worked answer →
Recommend solid state (an external SSD or large SD/memory card).
Speed: solid state has no moving parts and very fast read/write, so large photo files load and save quickly while editing. Portability: it is small, light and easy to carry between locations. Durability: with no moving parts it survives being knocked or dropped far better than a magnetic hard disk, which matters for a photographer travelling. Capacity: modern SSDs and cards offer enough capacity (hundreds of gigabytes or more) for large numbers of high-resolution photos.
A trade-off to acknowledge: solid state costs more per gigabyte than a magnetic hard disk, so if budget were the priority a portable HDD would be cheaper but slower and less durable.
Markers reward a clear recommendation plus three justified points linked to the scenario (portable, fast editing, surviving travel), and credit a sensible trade-off (cost).
Related dot points
- The need for primary storage, the purpose and characteristics of RAM and ROM, the differences between them, and the need for virtual memory.
An OCR J277 1.2.1 answer on the need for primary storage, the purpose and characteristics of RAM and ROM, the differences between them, and why virtual memory is needed.
- Why data must be represented in binary, the units of information (bit, nibble, byte, kB, MB, GB, TB, PB) and how to convert between them.
An OCR J277 1.2.3 answer on why computers use binary, the units of information from bit and nibble up to petabyte, and how to convert between units of data capacity.
- The need for compression and the difference between lossy and lossless compression, with their typical uses.
An OCR J277 1.2.5 answer on the need for data compression and the difference between lossy and lossless compression, including how each works and their typical uses.
- The purpose of utility software, and the purpose of encryption software, defragmentation software, data compression and backup utilities (full and incremental).
An OCR J277 1.5.2 answer on the purpose of utility software and the specific roles of encryption software, defragmentation software, data compression and backup utilities, including full and incremental backups.
- How to investigate and discuss computer science technologies while considering ethical, legal, cultural, environmental and privacy issues, and how to identify the stakeholders affected by a given technology.
An OCR J277 1.6.1 answer on how to investigate a digital technology against the five impact categories (ethical, legal, cultural, environmental and privacy), how to identify the stakeholders affected, and how to structure a balanced extended-response answer.
Sources & how we know this
- OCR GCSE (9-1) Computer Science (J277) specification — OCR (2020)