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Differences Between Real-Time and Time-Sharing Operating Systems

In this tutorial, we will learn about the real-time and time-sharing operating systems, differences between them. By Monika Jha Last updated : May 05, 2023

The types of operating systems are Time Sharing OS and Real-Time operating system. These can be differentiated in many ways.

What is Real-Time Operating System?

Real-time systems are considered as special-purpose systems where are need of fixed amount of time on the operation of a processor or the flow of data and to respond to the inputs to perform the task.

• The processing of the given input or data must be done within the given time constraints otherwise the system fails.
• The logical result or output of the computation produces by the system and the time to produce the result describes the accuracy of the system.
• Real-time systems are medical imaging systems, industrial control systems, home appliance systems, automobile-engine fuel injection systems, and weapon systems, etc.
• Real-time systems fetch data from sensors after that process it and provide output before the time constraints as it has well defined fixed time constraints.
• It contains methods for real-time scheduling tasks.
• There are two types of real-time operating systems: i) Hard real-time systems and ii) soft real-time systems.

i. Hard Real-Time System

In a hard-real time system, the system must perform the task within the given time constraints. If there is a single failure in the system to meet the deadline is a complete or catastrophic system failure.

Air Traffic Control systems, missiles, and nuclear reactor control systems are some examples of hard real-time systems.

ii. Soft Real-Time System

In a soft real-time system, it is less restrictive as producing output within a specified deadline is not necessary.

There can be a small tolerance. Missing the deadline is not considered as a total system failure but the performance is considered to be degraded.

Multimedia streaming, digital audio, and virtual reality are some examples of soft real-time systems.

What is Time Sharing Operating System?

It is the extension of the multi-programming operating system. Here extension is that the user can interact with the program running.

• Among multiple user processors, time can be shared. The small amount of time is assigned to each job at once and then move on to the next task. This user can obtain output from the program and can input another command and wait for that output.
• Many users can use the same computer at the same time and each user can interact with the system. By switching from one program to another, it makes an illusion that each process has its processor. Before switching to the next process, it produces the output of the currently running program.

Difference Between Real-Time Time-Sharing Operating Systems

The following are the main differences between real-time time-sharing operating systems:

1. In RTOS a computational task is accomplished within a specified amount of time whereas in Time-Sharing OS emphasis is providing a quick response to a request.
2. In RTOS process deals with one application at a time but in Time-Sharing OS process deals with more than one application simultaneously.
3. Switching does not present in a real-time system whereas it takes place in a time-sharing system.
4. In RTOS a process can retain the resources for a fixed amount of time and can be reallocated to another process after that time but users can share resources in real-time systems.
5. The modification does not take place in RTOS. In a real-time system, any modification in the program can be possible.
6. In real-time system users should get a response within a fraction of time but if not results are disastrous. In a time-sharing system, the response should get within fractions of seconds but if not, the results are not disastrous.

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