2. Clock speed
Computers can only do one thing at a time. It may appear that many things are happening simultaneously, for example you may be listening to music while writing an essay and also downloading some software in the background.
In reality, the computer can only process one instruction at a time. It is just that the machine is so fast, to you, everything seems to happen at once.
A CPU processes digital data by taking each piece of data one-at-a-time and doing something with it. The amount of time that it has to process each piece of data is controlled by a quartz clock inside the CPU.
With every tick of the clock, the CPU is able to process one piece of data or execute 
one instruction.
The CPU clock speed is measured in cycles per second. 1 cycle per second is also known as 1 Hertz
A computer running at 1GHz can carry out a thousand million instructions per second.
The clock on a modern desktop computer runs extremely quickly, typically three thousand million times a second (3 GHz).
It is hard to imagine just how fast this is, but it does mean that a CPU running at this clock speed can handle a huge amount of data in a very short time. This is why you can listen to music on the computer while you are also browsing the web and doing some work.
Naturally the speed of the clock determines the basic performance of the CPU - the faster it goes, the more powerful the computer.
Clock speed higher |
Clock speed lower |
|---|---|
| faster performance but runs hotter and consumes more power. | lower performance, less costly, needs less power - so good for battery life in laptops. |
Thus, if you wish to improve the performance of a computer, you could select a machine that has a faster CPU.
Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Clock speed