Overall processor performance relies on other internal and external factors, one of which is the processor's front side bus (FSB) speed, two common figures for the Intel Pentium 4 are 533MHz and 800MHz.
The front side bus consists of two channels, one for transferring data, and one for indicating the memory address where the data is to be retrieved from or stored.
The front side bus transfers data between the processor and the computer's other components such as memory, hard drives, etc. The FSB will have a certain width (measured in bits) which dictates how many bits can be transferred at any one time. As the 533MHz and 800MHz figures suggest, the FSB also has a clock cycle frequency indicating how fast the data can be transferred.
For example a processor having a FSB width of 32-bits and running at 533MHz, can transfer a set of 32-bits of data, 533,000,000 times a second.
