[Tech] How to determine the bus bandwidth.

Hi recently I had a need to find out the bus bandwidth. 
The bus had 64 lines and assume that the speed of the bus is xMHz.
This implies the bandwidth = (no.of lines) * (speed of each line).
Bus Bandwidth = ((64/8)*x*10^6)/(2^20) MBytes/sec.

A simple use of this metric is suppose you have 
SMP(Shared memory processors) with a common bus
and the bandwidth of the bus is 1 GBytes/sec
and you have several processors which have an 
(memory) Instruction bandwidth of 250 MBytes/sec
you cannot connect more than 4 processors to 
saturate the bus.