Difference Between Time Sharing OS and Multiprogramming OS

Operating systems play a vital role in managing computer resources and providing a platform for executing programs. Two common types of operating systems are Time Sharing Operating Systems and Multiprogramming Operating Systems. While both aim to improve resource utilization and user experience, they differ in their approach to achieving these goals.

Time Sharing Operating Systems

Time Sharing Operating Systems (TSOS) focus on providing an interactive computing environment where multiple users can simultaneously access the system and share its resources. TSOS achieves this by rapidly switching between different user programs, giving each user the illusion of having dedicated access to the system. This switching is done at such a fast pace that it creates an illusion of parallelism. Key features of Time Sharing Operating Systems include −

  • Resource Allocation − A time-sharing operating system allows multiple users to share the resources of a single computer system by dividing the CPU time into small time intervals called time slices or quantum. Each user or task is given a fair and equal portion of the CPU time.

  • Interactivity − Time-sharing OS emphasizes interactivity, providing quick response times to user inputs. It allows users to interact with the system through terminals or consoles, enabling multiple users to run programs simultaneously and receive prompt feedback.

  • Context Switching − Time-sharing OS relies on frequent context switching between different user programs. It saves the state of the currently running program and restores the state of the next program in the queue, allowing each program to execute for a short time before switching to another.

  • Scheduling − Time-sharing OS uses scheduling algorithms (e.g., round-robin, priority-based) to determine the order in which tasks are executed. The goal is to provide fair and equitable access to system resources, ensuring that no user or program monopolizes the CPU for an extended period.

  • Response Time − The primary objective of a time-sharing OS is to minimize response time and provide interactive performance. Users should experience quick feedback and smooth execution of their tasks, even if there are multiple users or programs running concurrently.

Multiprogramming Operating Systems

Multiprogramming Operating Systems (MPOS) focus on maximizing CPU utilization by allowing multiple programs to reside in memory simultaneously. Unlike TSOS, MPOS doesn't provide the illusion of parallel execution to users. Instead, it aims to keep the CPU busy at all times by swiftly switching between programs whenever one is waiting for an I/O operation or is blocked. Key features of Multiprogramming Operating Systems include−

  • Resource Utilization − A multiprogramming operating system aims to maximize the utilization of system resources by executing multiple programs simultaneously. It allows multiple programs to reside in the memory concurrently, taking advantage of idle CPU and I/O time.

  • Parallel Execution − In a multiprogramming OS, several programs are loaded into memory simultaneously, and the CPU switches between them based on their availability and priority. This enables parallel execution of programs, resulting in improved throughput and resource utilization.

  • Efficiency − Multiprogramming OS reduces the idle time of system resources by keeping the CPU and other peripherals busy. When one program is waiting for I/O, the CPU can switch to another ready program, allowing optimal utilization of the available resources.

  • Process Management − A multiprogramming OS manages processes by allocating CPU time to each process for a fixed duration or until it voluntarily releases the CPU. It employs scheduling algorithms to determine the order in which processes are executed, aiming to maximize CPU and I/O utilization.

  • Throughput − The primary objective of a multiprogramming OS is to increase throughput, which refers to the number of programs completed per unit of time. By allowing concurrent execution of multiple programs, it can complete more tasks in a given time frame.

Differences Between Time Sharing OS and Multiprogramming OS

The following table compares and contrasts the different features of Time Sharing OS and Multiprogramming OS −


Time Sharing OS

Multiprogramming OS

Execution Model

Provides the illusion of parallel execution to multiple users by rapidly switching between programs.

Maximizes CPU utilization by switching between programs while one is waiting for I/O operations.

User Interaction

Emphasizes interactive response times, providing users with a responsive and interactive computing experience.

Prioritizes CPU utilization and overall system throughput, with less emphasis on interactive response times.

Resource Allocation

Focuses on fair resource allocation among multiple users, ensuring each user gets a fair share of system resources.

Aims to maximize overall CPU utilization, with resource allocation policies optimized for efficient program execution.

Context Switching

Frequent context switching occurs between different user programs to provide the illusion of parallelism.

Switching occurs when a program is waiting for an I/O operation or is blocked, maximizing CPU utilization.

Program Isolation

Programs executed concurrently share the system's resources, but mechanisms are in place to maintain isolation and prevent interference.

Programs running concurrently are isolated from one another to maintain data integrity and prevent interference.

Primary Objective

Provide a responsive and interactive environment for multiple users.

Maximize CPU utilization and overall system throughput.

User Experience

Users experience the system as if they have exclusive access to it, with quick response times and interactive capabilities.

Users may experience occasional delays, but the system prioritizes overall program execution and throughput.


Time Sharing Operating Systems prioritize providing a responsive and interactive environment for multiple users, while Multiprogramming Operating Systems focus on maximizing CPU utilization and overall system throughput. The choice between the two depends on the intended use case, the nature of the applications, and the trade-offs between interactivity and throughput.

Updated on: 13-Jul-2023


Kickstart Your Career

Get certified by completing the course

Get Started