Multiprogramming and multitasking are the aspects of a computer system. However, these are also the types of operating system. The prior difference between multiprogramming and multitasking is that the multiprogramming is based on preemptive scheduling where the major pondering point is the CPU idleness. On the other hand, in the multitasking system, the CPU jobs have equal time interval for processing and it emphasis on responsiveness.
The multiprogramming system is advantageous in terms of utilization of the system resources such as CPU, memory and peripheral devices. Although it does not employ any interaction between users. Inversely, the multitasking system combines CPU scheduling and multiprogramming, so that each user will get a small part of the time-shared computer where communication between users also takes place.
Content: Multiprogramming Vs Multitasking
|Basis for comparison||Multiprogramming||Multitasking|
|Basic||Enables multiple programs to utilize CPU simultaneously.||A supplementary form of the multiprogramming system also supports user interaction.|
|Objective||Improvement in CPU utilization.||Minimize the response time.|
|Switching||Occurs when the currently running process stops.||Carried out each time after the time slice of process is finished.|
Definition of Multiprogramming
An operating system has the ability to multiprogram where it can involve multiple programs to be executing over a single CPU. Multiprogramming is an essential aspect of the operating system which can significantly induce CPU utilization. It arranges the jobs (code and data) in a way that the CPU will always have one job to execute. Here the concept is that operating system stores multiple jobs in the memory at the same time. As the main memory can short out for accommodating all jobs. So, the disks are used for storing the CPU jobs initially.
The group of jobs in the memory could be the subset of the jobs residing in the job pool. To process these jobs the operating systems selects one of them and starts to execute it in the memory. Ultimately, if any of the jobs have to wait for a specific time period for some other task to finish like I/O operation or other instruction, the CPU switches to the other job for that period. It stops CPU for being idle till only one job is left as it switches from one to the other job if it transitions to waiting state. Regardless, in a non-multiprogramming system, the CPU must be resting in an idle state.
Definition of Multitasking
Multitasking is viewed as the logical extension of the multiprogramming, as it implements the same approach of switching between the jobs but here switching is very often. This frequent switching facilitates the user to interact with each program while it is running. Multitasking systems need an interactive computer system to permit communication between the users and the system.
The user gives instructions to the computer system or to the program directly using some input devices like a mouse or keyboard. Consequently, the result of the input is immediate where the response time is less and could range in milliseconds to seconds. It permits multiple users to share common resources simultaneously. As the action or command in the multitasking system is often short and requires little CPU time for each user. Since the switching in these systems is very fast, the users are not able to notice it, and it gives the perception of a dedicated system.
Key Differences Between Multiprogramming and Multitasking
- The multitasking supports user communication which is not provided in a multiprogrammed system.
- Multiprogramming is mainly implemented to increase CPU utilization by arranging programs in such a way that the CPU will always have one program to execute. On the contrary, the aim of the multitasking is to improve the response time through sharing the computing resources among the multiple users.
- In multiprogramming, the context switching is done when the currently executing process halts and the CPU is allocated to some other process. As against, in multitasking systems, the switching occurs when the time slice of currently executing process gets over.
- The multitasking systems are more complicated as compared to multiprogramming systems. It also offers more protection and separation to the co-resident programs.
Multitasking systems can be considered as multi-programmed as it runs several programs at the same time. However, a multiprogramming system is not necessarily multitasking.