Difference between Single and Multiprocessor Systems

Parameter	Single Processor Systems	Multiprocessor Systems
Description	If a System contains only one processor for processing than it is called single processor system.	If a System contains two or more than two processors for processing than it is called multiprocessor system.
Use of Co-Processors	Yes, Single Processors uses multiple Controllers that are designed to handle special tasks and can execute limited instruction sets. E.g. DMA Controller, North/South Bridge.	In Multi Processor Systems Two Types of approaches are Used: 1)      Symmetric Multiprocessing(SMP) 2)      Asymmetric Multiprocessing In Asymmetric Multiprocessing one Processor works as Master and Second Processor act as Slave And in Symmetric Multiprocessing each processor performs all the tasks within the operating system.
Throughput	Throughput of Single Processor Systems is less than Multiprocessor Systems Because each and every task is performed by the same processor.	Throughput of Multiprocessor systems is greater than single processor systems. If a System Contains N Processors than its throughput will be slightly less than N because synchronization must be maintained between two processors and they also share resource which increases certain amount of overhead.
Cost Economic	Single Processor Systems cost more because each processor requires separate resources.i.e. Mass Storage, Peripherals, Power Supplies etc.	Multiprocessor Systems cost less than equivalent multiple single processor systems because they uses same resources on sharing basis.
Design Process	It is Easy to design Single Processor Systems.	It is difficult to design Multi Processor Systems because Synchronization must be maintained between processors otherwise it may result in overloading of one processor and another processor may remain idle on the same time.
Reliability	Less reliable because failure in one processor will result in failure of entire system.	More reliable because failure of one processor does not halt the entire system but only speed will be slow down.
Examples	Most of Modern PCs.	Blade Servers.

This also Applies to:
Difference between Single and Multiprocessor Systems
Difference between Single and Multiprocessor Architecture