The unit that a CPU's performance is measured in CPU's performance is dependent on its speed and clock rate. Both the speed and clock rate is measured in hertz or Hz. A core works on one task while another core works on a different task. So the more cores a CPU has, the faster and efficient the computer will be. Single Core CPUs; Single core CPUs are the oldest computer CPUs. These CPUs can only focus on one operation at a time so they were not very good at multi-tasking.
