11.3.1.4 compare single-user and multi-user operating systems
11.3.1.5 compare one-task and multitasking operating systems
Types of operating systems
Multi-user vs. Single user
Single user OS
Single-user operating systems can only be used by one user at a time.
A few examples of single-user OS: – DOS – Windows – Linux
Don’t be confused with multiple accounts on a computer...for someone else to use their account you have to log off yours first!
These systems are also known are single-application OS. As one application is concentrated at a time. These systems require fewer resources and can do processing in a queue. The recurring tasks are performed well in these systems. For example, making payroll or salaries of employees.
Advantages
Disadvantages
Supports one user at a time Ensures that system resources are fully dedicated to one user, providing optimal performance for their tasks.
Easy to maintain With fewer features and simpler architecture, it is easier to troubleshoot, update, and manage.
Less chance of damageLimited access reduces the risk of accidental or intentional damage caused by multiple users.
Concentrate on one taskOptimized for handling one process or task efficiently, leading to better performance and minimal resource contention.
Tasks take longer time to completeThe system can handle only one task at a time, making it less efficient for multitasking or parallel processing.
Idle time is higherSystem resources may remain underutilized when the user is not actively using them, leading to inefficiency.
Multi-user OS
Allow lots of users to share data and resources at (apparently) the same time. This is called a network.
A server controls how the computers run and communicate.
The server needs a Network Operating System (NOS), for example, Microsoft Windows Server, UNIX, Linux, Mac OS X, Novell NetWare, BSD, etc...
A multi-user operating system allows multiple users to access a computer system concurrently.
Time-sharing systems can be classified as multi-user systems as they enable multiple user access to a computer through the sharing of time.
Advantages
Disadvantages
Highly stable centralized serversEnsures consistent performance and reliability by managing resources and services from a centralized location.
Enhanced securitySecurity is managed at the server level, providing controlled access, user authentication, and protection against unauthorized activities.
Remote accessAllows users to access the server from various locations and devices, enabling flexibility and productivity in different environments.
High server costsSetting up and maintaining centralized servers can be expensive due to hardware, software, and infrastructure requirements.
Dependency on central locationUsers rely on the central server for most operations, which can cause delays or disruptions if the server experiences issues.
Regular maintenance and updatesContinuous updates, monitoring, and maintenance are necessary to ensure optimal performance and security, requiring skilled personnel and additional resources.
Multitasking vs. Single-tasking
Single-tasking OS
Advantages
Disadvantages
Low resource requirementsRequires minimal memory and processing power, making it suitable for low-spec devices.
Reduced risk of conflictsNo competing tasks mean fewer chances of system crashes or resource contention.
Single task limitationThe system can only handle one task at a time, making it inefficient for multitasking or handling multiple processes simultaneously.
Lack of protectionThere is no isolation between the operating system and user programs, increasing the risk of errors or crashes affecting the entire system.
No file ownershipFiles are not associated with specific users, which can lead to security and organizational issues, as anyone can access or modify files without restrictions.
Multitasking OS
Advantages
Disadvantages
Timesharing Multitasking allows for timesharing, where the CPU is divided into multiple time slices, allowing multiple programs or tasks to be executed concurrently. This improves overall system efficiency and user productivity.
Handle multiple users Multitasking operating systems can handle multiple users simultaneously, enabling collaborative work and resource sharing in multi-user environments such as servers or shared workstations.
The user can use multiple programs Users can run multiple programs or applications simultaneously, switching between them seamlessly. This enhances productivity by allowing users to work on different tasks or utilize various software tools concurrently.
Efficient virtual memory Multitasking OSs efficiently manage virtual memory, allowing multiple programs to utilize memory resources effectively. They allocate memory space dynamically, optimizing memory usage and minimizing wastage.
CPU idle time can be reduced Multitasking OSs minimize CPU idle time by allocating CPU resources to different tasks based on priority and scheduling algorithms. This ensures maximum utilization of the CPU, enhancing system performance.и
Limitation of memory Multitasking OSs require sufficient memory resources to accommodate multiple programs or tasks simultaneously. In cases of limited memory availability, system performance may degrade, leading to slowdowns or even crashes.
Limitation of the processor The processor's capabilities can pose limitations on multitasking. If the processor is not powerful enough or lacks multiple cores, the performance of concurrent tasks may suffer, affecting system responsiveness.
CPU heat up Intensive multitasking can lead to increased CPU usage and subsequently higher heat generation. This may cause the CPU temperature to rise, potentially leading to thermal throttling or system instability if proper cooling measures are not in place.
Reliability problem With multiple programs or tasks running simultaneously, there is an increased chance of system instability or conflicts. If one program or task encounters an error or crash, it can potentially affect the stability of other running processes, leading to system-wide issues.
Questions:
There are common functions of different types of operating systems, such as ...
A PC is a multitasking machine. What does it mean? Is it the same thing as multiprocessing?
What are the advantages of multitasking?
The difference between single-user and multi-user operating systems is ...
The difference between one-task and multitasking operating systems is ...
Exercises:
Ex. 1. Find pairs
Ex. 2. Distribute advantages and disadvantages of OS types
