A typical computer system is interconnected with a number of different buses, both internal and external. The diagram includes multiple cache buses, an external CPU bus, PCI-Express buses, a parallel PCI bus, SATA buses, USB ports, and more. What are the advantages of providing multiple buses rather than connecting everything together with a single bus?
Advantages of multiple buses over a single bus:
A typical computer is interconnected with a number of different buses. Examples include, Internal buses, such as PCI-Express, SATA or external buses such as USB. Instead of a single bus, modern computers have a number of these interconnected buses. This architecture provides the following advantages:
1) A single bus can carry only a single signal at a time and hence in a shared configuration, all the other components will have to wait for their signal to be carried, thus reducing system performance.
2) The various components also need to communicate with each other on who gets to use the shared system bus at a time, thus wasting time.
3) The system bus needs a clock speed which is much slower than the CPU speed and is constrained by the furthest components.
Hence modern configuration includes interconnected buses instead of a single shared bus.