These intervals are generated by the clock unit . Every operation within the CPU takes place at the clock pulse. No operation, regardless of how simple, can be performed in less time than transpires between ticks of this clock. But some operations require more than one clock pulse. The faster the clock runs, the faster the computer performs .
Larger systems are even faster.
The word size is the number of bits the CPU can process at a time. An 8-bit processor manipulates with 8 bits simultaneously. For an 8-bit CPU, it will take four operations, a separate operation for addition of each of the four digits. A 16-bit processor will be able to work on two digits simultaneously, so it will need only two operations. A 32-bit processor will complete addition in one operation.