---
title: "Parallelism and features of an OS"
subject: "Microprocessor"
chapter: 6
key: "semester_4/microprocessor:parallelism-and-os-features"
source: https://www.bctengineer.com/q/semester_4/microprocessor/parallelism-and-os-features
site: BCT Engineering
---

# Parallelism and features of an OS

Microprocessor · Chapter 6: Advanced Topics

- Asked in: 2071 Bhadra, 8 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/microprocessor/parallelism-and-os-features
- Whole chapter: https://www.bctengineer.com/md/semester_4/microprocessor/chapter-6

## Question

What do you mean by parallelism? Write and explain the features of a typical operating system.

## Short answer

Parallelism is executing multiple operations at the same time, using multiple cores or time-sharing. Typical OS features include process and memory management, file and device management, security, user interface, resource accounting, error handling, networking, and deadlock handling.

## Answer

#### Parallelism

Parallelism is the ability of a system to carry out several operations or tasks at the same time. It is used to raise speed and throughput. Types:

- **Instruction-level:** pipelining and superscalar execution overlap instructions inside one CPU.
- **Thread/process-level:** multiple threads or processes run on multiple cores or processors.
- **Data-level:** the same operation on many data items (SIMD, vector processing).
- It may be real (more than one CPU) or pseudo (time-sharing on one CPU).

#### Features of a typical operating system

1. **Process management:** creation, scheduling, termination, synchronisation and communication of processes; multitasking.
2. **Memory management:** allocation, protection and virtual memory (paging/segmentation).
3. **File management:** files and directories, access rights, storage allocation.
4. **Device management:** device drivers, buffering and spooling for I/O devices.
5. **Security and protection:** authentication and access control.
6. **User interface:** command line or GUI.
7. **Resource management and accounting:** fair use of CPU, memory and devices.
8. **Error handling:** detection and recovery from errors.
9. **Networking support** and **interrupt and deadlock handling.**

The OS uses parallelism features of the hardware, such as multiple cores, to run many processes together.

## Check yourself

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

1. What does parallelism mean?
   A. Running one task faster by raising the clock frequency
   B. The ability of a system to carry out several operations or tasks at the same time
   C. Storing several programs in memory but running one at a time
   D. Splitting memory into pages and segments
   Answer: B. Parallelism is doing several tasks at the same time, which raises speed and throughput. (Key point: Definition of parallelism)

2. Which type of parallelism applies the same operation to many data items, as in SIMD or vector processing?
   A. Instruction-level
   B. Thread/process-level
   C. Data-level
   D. Pseudo-parallelism
   Answer: C. Data-level parallelism performs one operation on many data items at once (SIMD, vector processing). (Key point: Data-level parallelism)

3. Time-sharing of a single CPU among several tasks is an example of which kind of parallelism?
   A. Real parallelism
   B. Pseudo parallelism
   C. Instruction-level parallelism using superscalar units
   D. Data-level parallelism
   Answer: B. Pseudo parallelism uses time-sharing on one CPU; real parallelism needs more than one CPU. (Key point: Real vs pseudo parallelism)

4. Which OS feature covers device drivers, buffering and spooling for I/O devices?
   A. Memory management
   B. File management
   C. Security and protection
   D. Device management
   Answer: D. Device management handles I/O devices through drivers, buffering and spooling. (Key point: Device management feature of OS)

## Related in Microprocessor

- [Features of a typical operating system](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Afeatures-of-operating-system) — Microprocessor, chapter 6, asked 3×
- [Parallelism, IPC deadlock and OS role](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Aparallelism-deadlock-os-role) — Microprocessor, chapter 6
- [Real and pseudo-parallelism](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Areal-pseudo-parallelism) — Microprocessor, chapter 6

## Related in other subjects

- [OS abstraction, extended machine, system call](https://www.bctengineer.com/question.md?key=semester_6%2Foperating_system%3Aos-abstraction-system-call) — Operating System, chapter 1
- [Typical water supply system and components](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Atypical-ws-system-components) — Water Supply Engineering, chapter 1, asked 4×
- [Typical power system network and components](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Atypical-power-system-network-components) — Power System Analysis I, chapter 1
- [Typical power system with voltage levels](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Atypical-power-system-voltage-levels) — Power System Analysis I, chapter 1