Know that the speed (operating frequency) of the CPU is measured in megahertz (MHz) or gigahertz (GHz).

Type and Speed
The performance or speed of a processor depends on the 'clock rate'.

The performance of the memory hierarchy also greatly affects processor performance.

Processing performance of computers is increased by using multi-core processors, which essentially is plugging two or more individual processors (called cores in this sense) into one integrated circuit.

In a perfect world a dual core processor would be roughly twice as powerful (and fast) as a single core processor. In reality the performance improvement is far less, usually around fifty percent.