The terms bus, bus type, and bus speed refer to the collection of wires and integrated circuits through which data is transmitted from the processor to other components inside of the computer.
What Exactly Is A Bus Type?
Bus type defines the standard for how components transfer data, while bus speed defines how fast the components can transfer data.
A bus type's performance is measured in megahertz (Mhz) and gigahertz (Ghz). For example, the obsolete 80386 processor communicated with other peripheral devices using a 16-bit data bus. This meant that it could only transmit data using 16 bits at one time. The Pentium processor transferred data through a 32 bit data bus which meant the system could transmit up to 32 bits of data at any given time.
The Pentium processor could transmit data at a 100 Mhz bus speed. The early celeron processors could transfer at only 66 Mhz. A Pentium IV processor also transfers data using a 32 bit data bus but at a much higher speed or frequency, often ranging in speeds from 400 Mhz to 800 Mhz depending on the processor and motherboard being used.
Overview Of Bus Types
In a personal computer there are five different bus types. They are outlined below.
North Bridge and South Bridge
All motherboards have two internal bus types respectively labelled Northbridge and Southbridge. They are commonly referred to as bridges because the link to various other components on the motherboard.
There are several different chips integrated into a motherboard that govern how functions are controlled within each chipset. For example, the Northbridge chipset controls the memory and graphics systems.
The southbridge chipset controls storage interfaces, the BIOS settings, and additional peripheral devices such as audio, lan, and other bells and whistles incorporated into the design of the motherboard.
The graphics bus defines how fast data flows from the CPU to the North chipset and eventually to your computer's monitor.
To see output on your computer screen you need some type of display system. This introduces two variables: the video card, and the interface in which the video card should connect. A graphics bus is typically measured in
The north bridge chipset also controls data stored in memory banks inside the computer. Commonly referred to as memory controller hub, this provides a means for the CPU and other components to store and retrieve data as needed.