Prerequisite – Different types of Operating System
1. Time Sharing : Time Sharing is the logical extension of multiprogramming, in this time sharing Operating system many users/processes are allocated with computer resources in respective time slots. In this the processors time is shared with multiple users that’s why it is called as time sharing operating system. It has a fixed time slice for the different processes. Its main purpose is interactive response time.
Benefits of Time Sharing OS :
- Quick response.
- Reduces CPU idle time.
- All the tasks are given specific time.
- Less probability of duplication of software.
- Improves response time.
Disadvantages of Time Sharing OS :
- It consumes much resources.
- Requires high specification of hardware.
- It has a problem of reliability.
- Security and Integrity concerns.
- Probability of data communication problem.
2. Multiprogramming : Multiprogramming operating system allows to execute multiple processes by monitoring their process states and switching in between processes. In this processor and memory underutilization problem is resolved and multiple programs runs on CPU that’s why it is called multiprogramming. It has no fixed time slice for processes. Its main purpose is resource utilization.
Benefits of Multiprogramming OS :
- No CPU idle time.
- Tasks runs in parallel.
- Shorter response time.
- Maximizes total job throughput of a computer.
- Increases resource utilization.
Disadvantages of Multiprogramming OS :
- Sometimes long time jobs have to wait long time.
- Tracking of all processes sometimes difficult.
- Requires CPU scheduling.
- Requires efficient memory management.
- No user interaction with any program during execution.
Difference between Time Sharing and Multiprogramming :
| S.No. | TIME SHARING | MULTIPROGRAMMING |
|---|---|---|
| 01. | Time Sharing is the logical extension of multiprogramming, in this time sharing Operating system many users/processes are allocated with computer resources in respective time slots. | Multiprogramming operating system allows to execute multiple processes by monitoring their process states and switching in between processes. |
| 02. | Processors time is shared with multiple users that’s why it is called as time sharing operating system. | Processor and memory underutilization problem is resolved and multiple programs runs on CPU that’s why it is called multiprogramming. |
| 03. | In this process, two or more users can use a processor in their terminal. | In this, the process can be executed by a single processor. |
| 04. | Time sharing OS has fixed time slice. | Multi-programming OS has no fixed time slice. |
| 05. | In time sharing OS system, execution power is taken off before finishing of execution. | In multi-programming OS system before finishing a task the execution power is not taken off. |
| 06. | Here the system works for the same or less time on each processes. | Here the system does not take same time to work on different processes. |
| 07. | In time sharing OS system depends on time to switch between different processes. | In Multiprogramming OS, system depends on devices to switch between tasks such I/O interrupts etc. |
| 08. | System model of time sharing system is multiple programs and multiple users. | System model of multiprogramming system is multiple programs. |
| 09. | Time sharing system minimizes response time. | Multiprogramming system maximizes processor use. |
| 10. | Example: Windows NT. | Example: Mac OS. |