Difference between Multiprogramming and Multitasking
The operating system is an essential component of software that controls the computer’s hardware and other software programs. It can be described as a middleman. The user cannot directly issue commands to the CPU in machine language, nor can the CPU directly communicate with the user. As a result, a middleman is required to communicate and translate all interactions between the user and the CPU.
Apart from doing basic tasks like managing peripheral devices, displaying output on the screen, and tracking data and files, the operating system also performs higher-level functions such as multiprogramming and multitasking.
In this article, you will learn the difference between multiprogramming and multitasking. But before discussing the differences, you need to know about multiprogramming and multitasking.
What is Multiprogramming?
A multiprogramming operating system can run several programs on a single processor machine. If a single application has to wait for I/O transfer in a multiprogramming operating system, other programs are always ready to use the CPU. As a result, numerous jobs can share the CPU’s time. However, in a multiprogramming operating system, it is not predefined that their jobs would be executed simultaneously.
If a program is in the process of being executed, it is referred to as a “Process”, “Job”, or “Task”. Simultaneous program executions help increase system resource utilization and system throughput performance compared to serial and batch processing systems.
Advantages and disadvantages of multiprogramming
There are various advantages and disadvantages of multiprogramming. Some of them are as follows:
- It provides high CPU utilization.
- It has a shorter response time.
- It can assign priority to the jobs.
- Its scheduling implementation is not easy.
- It required more management.
What is Multitasking?
Multitasking means working on multiple tasks simultaneously, such as using your computer while listening to music. Also, using a browser, search for something on the internet and create a word document that is your assignment. It appears that all of the tasks are taking place at the same time. It is not all of the tasks happening simultaneously; the processor moves between them at such a fast pace that we believe they are happening simultaneously.
Multitasking is similar to multiprogramming in that the CPU is assigned to a process for a specified period of time, i.e., ‘Time quantum or time slice’, after which the CPU ‘Context switches’ to another process. It runs various programs at the same time.
The PC requires a huge memory to execute multitasking (RAM or ROM). Its primary goal is to improve the timing of the CPU’s response. Users can engage with the system during multitasking, for example, by typing a letter while the printing process is running.
Multitasking is a highly complicated system. It is based on the time slice principle, which assigns a fixed amount of time to each activity to be completed. It is especially useful when a program requires a high level of parallelism. It provides a set amount of time for each program to run.
Advantages and disadvantages of multitasking
There are various advantages and disadvantages of multitasking. Some of them are as follows:
- It provides logical parallelism.
- It provides a shorter response time.
- It provides CPU utilization.
- It couldn’t be executed on a slow-speed processor.
- It needs a large amount of storage memory to do the work.
Main Differences between the multiprogramming and multitasking
There are various main differences between multiprogramming and multitasking. Some of them are as follows:
- Multiprogramming is mostly used to maximize CPU utilization by organizing applications always to have one program to execute. On the other hand, multitasking aims to enhance reaction time by sharing computing resources across several users.
- Multiprogramming is primarily focused on increasing CPU use. The programs are organized so that the CPU will never idle; it will always execute one program after another. On the other hand, multitasking tries to improve CPU reaction time.
- Multiprogramming is built on the concept of context switching, which is a usual procedure that allows the CPU to transition from one process to another while using a single processor machine. The Process Control Block (PCB) preserves the state of an active process for the CPU to resume from the same location. On the other hand, multitasking is based on time-sharing, and it completes tasks in the same amount of time for each activity or process.
- Both the terms have almost identical meanings and the common term used in modern operating systems, although they serve different purposes. Multiprogramming is primarily dependent on a computer’s ability to store programs for a longer period to decrease CPU idle time. The scheduling algorithm is used to allocate processes. The operating system runs a portion of one program at a time, followed by a portion of another program, etc. On the other hand, the CPU permits numerous processes to operate concurrently through time-sharing and executes them properly in a multitasking operating system.
- Multiprogramming takes maximum time to execute any process, whereas multitasking takes minimum time to execute any process.
- Multiprogramming may be done on a computer with a small amount of RAM or ROM memory; it doesn’t need a huge memory. On the other hand, multitasking necessitates a huge amount of memory storage to complete all jobs or processes simultaneously.
Head to head comparison between multiprogramming and multitasking
Here, there are various head-to-head comparison between multiprogramming and multitasking. Some of them are as follows:
|Basic||It allows multiple programs to utilize the CPU simultaneously.||A supplementary of the multiprogramming system also allows for user interaction.|
|Mechanism||Based on the context switching mechanism.||Based on the time-sharing mechanism.|
|Objective||It is useful for reducing/decreasing CPU idle time and increasing throughput as much as possible.||It is useful for running multiple processes at the same time, effectively increasing CPU and system throughput.|
|Execution||When one job or process completes its execution or switches to an I/O task in a multi-programmed system, the system momentarily suspends that process. It selects another process from the process scheduling pool (waiting queue) to run.||In a multiprocessing system, multiple processes can operate simultaneously by allocating the CPU for a fixed amount of time.|
|CPU Switching||In a multiuser environment, the CPU switches between programs/processes quickly.||In a single-user environment, the CPU switches between the processes of various programs.|
|Timing||It takes maximum time to execute the process.||It takes minimum time to execute the process.|
The two aspects of the modern operating system are multiprogramming and multitasking. Multiprogramming is the act of recording several processes in memory and then executing them one by one on a single processor. Multitasking is similar to multiprogramming in that the CPU is assigned to a process for a specific amount of time. It runs multiple programs simultaneously by utilizing multiple CPUs on the same system.