System architecture
- 2. Thread of execution Instructions and data Memory Device
- 3. Number of general purpose- processors • Single processor system • Multi processor systems
- 4. Single processor system: Most systems use single processor systems. They perform only one process at a given time, and it carries out the next process in the queue only after the current process is completed. OS monitors the status of them and also sends them next executable instruction. It relieves CPU of disk scheduling and other tasks. It is suitable for general purpose computers , as it cannot run multiple processes in parallel.
- 5. Multiprocessor system Incresed throughput Increased Reliability Economy of scale As there are a number of processors, more work can be done in less time. These multiple processors run parallel to each other increasing the performance of the system. Failure of any processor will not affect the functionality of the system, as there are a number of processors Multi Processor Systems cost less than a number of individual single processor system.
- 6. Multiprocessor system : Two or more processors will be in close communication with each other with shared memory, storage and power supply. Multiprocessor systems first appeared prominently appeared in servers and have since migrated to desktop and laptop systems. Recently, multiple processors have appeared on mobile devices such as smartphones and tablet computers.
- 8. Multiprocessor system Symmetric multiprocessing Asymmetric multiprocessing Each processor performs all tasks within the operating system. SMP means that all processors are peers; no boss– worker relationship exists between processors Each processor is assigned a specific task. This scheme defines a boss– worker relationship. The boss processor schedules and allocates work to the worker processors.