The Central Processing Unit (CPU) carries out all the computer program instructions.
Choosing the right CPU has a great impact on performance.
Two very popular choices of CPU for use in a PC are:
- The Pentium series from Intel
- The Athlon series from AMD
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Both series have products running over a range of clock speeds.
Selecting a suitable CPU includes the following performance criteria :-
| Clock speed - higher = faster performance but runs hotter and consumes more power. | |
| Clock speed - lower = lower performance, less costly, needs less power - so good for battery life in laptops. | |
| Bus width - 32 bit CPUs are now the main size, but both series have 64 bit versions as well. But it does mean that software needs to be re-written to take advantage of this. At the moment there isn't much 64 bit software around. | |
| Internal RAM - the more the better. Performance improves because data does not have to move between CPU and the external RAM chips. |
Of course higher performance means
higher price and so it is a balance between
what
is the minimum performance needed against the cost.
At the moment, clock speed range up to 3.8GHz.
MULTIPLE CPUs.
Another way of boosting performance is to use more than one CPU in the computer.
This is called 'parallel processing'.
Basically a computer program that has been especially written to work in
this way will split up its tasks so that both CPUs work at the same time.
Multiple CPU machine are still uncommon. But they will become a more popular choice as the main software companies design their products to make use of the computing power available.
