It is very difficult to build large multiprocessor systems.
The cost to build large multiprocessor systems are also very expensive.
Therefore to get rid of these problems, much research has been done on multicomputers.
Basically, multicomputers are tightly-coupled central processing units that don't share the memory.
In multicomputer, each central processing units has its own memory.
Generally, multicomputers are easy to build as the basic component is a stripped-down personal computer with the addition of a NIC.
Here, NIC stands for Network Interface Card.
To get high performance computer system, then just design the interconnection network and the interface card cleverly.
You will learn all about multicomputers in operating system in detail, divided into following tutorials: