---
title: "Multiprocessing versus multitasking"
subject: "Embedded System"
chapter: 6
key: "semester_6/embedded_system:multiprocessing-vs-multitasking"
source: https://www.bctengineer.com/q/semester_6/embedded_system/multiprocessing-vs-multitasking
site: BCT Engineering
---

# Multiprocessing versus multitasking

Embedded System · Chapter 6: RTOS

- Asked in: 2072 Asoj, 2 marks
- Video: [Multiprocessing and Multitasking in Embedded system Design](https://www.youtube.com/watch?v=Q7eyEMXrBLc) — Shree Rama channel
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/embedded_system/multiprocessing-vs-multitasking
- Whole chapter: https://www.bctengineer.com/md/semester_6/embedded_system/chapter-6

## Question

Differentiate between multiprocessing and multi tasking in RTOS.

## Short answer

Multiprocessing uses multiple CPUs for true parallel execution, increasing throughput and reliability. Multitasking shares a single CPU among tasks via time-slicing, improving responsiveness with lower hardware cost.

## Answer

| Point | Multiprocessing | Multitasking |
|---|---|---|
| Meaning | System with two or more CPUs (processors) executing in parallel | Several tasks share a single CPU by time slicing and switching |
| Processors | Multiple | One (or more) |
| Execution | True parallel execution | Apparent (concurrent) execution; one task at a time per CPU |
| Hardware cost | High | Low |
| Overhead | Needs CPU communication and sharing | Context-switch overhead |
| Purpose | Throughput, reliability | Better CPU use and responsiveness |
| Example | Dual-core processor | RTOS running 3 tasks on one microcontroller |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which gives true parallel execution?
   A. Multiprocessing with two or more CPUs
   B. Multitasking on one CPU
   C. Both always
   D. Neither
   Answer: A. Multiprocessing uses several CPUs at once; multitasking on one CPU is only apparent concurrency. (Key point: Parallelism)

2. How does multitasking share one CPU?
   A. Running every task on its own CPU
   B. Disabling other tasks
   C. Using separate memories
   D. Time slicing and switching among tasks
   Answer: D. Tasks take turns, incurring context-switch overhead. (Key point: Multitasking mechanism)

3. Which has the higher hardware cost?
   A. Multitasking
   B. Equal
   C. Multiprocessing
   D. Neither needs hardware
   Answer: C. Multiple processors raise hardware cost; multitasking needs only software on one CPU. (Key point: Cost)

## Related in Embedded System

- [RTOS versus general-purpose OS](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Artos-vs-gpos) — Embedded System, chapter 6, asked 4×

## Related in other subjects

- [One-class vs multi-class CF](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Acollaborative-filtering-one-vs-multi-class) — Information System, chapter 7