Title: Know some of the factors that impact on a computer’s performance
Course: Module 1, Concepts of Information and Communication Technology (ICT)

Computer performance

In this Lesson you will exmplore some of the factors that impact on a computer’s performance such as:

- CPU speed
- RAM size
- Disk space
- Number of applications running

Speed

The operating speed of a computer system depends on the time taken for hardware and software to interact and manipulate any necessary information. If one or more parts of a computer system operate slowly, the entire system can be slowed down. Below is a summary of the main factors that influence a computer’s speed:
- The clock speed of the CPU is one of the most important influences on the speed of a computer. A higher clock speed means more units of data can be processed each second. The clock speed of a CPU used to be measured in megahertz (MHz). However these days manufactured PCs have CPUs which are measured in gigahertz (GHz).

- Although the clock speed of the CPU is very important, and a good indicator of a computer’s speed, the type of CPU must also be considered. Different CPUs may be designed to process larger amounts of data at a time or process certain types of data more efficiently. When comparing different processors, the design may be as important as the clock speed. For example, an Intel Pentium 4 processor running at 2.0GHz may not be as fast as an AMD Athlon processor running at the same clock speed. This is because the Athlon generally has a more efficient design.

- The amount of cache RAM installed on components such as the CPU, motherboard and hard disk will affect the speed of the computer. Data stored in a component’s cache can be accessed and manipulated far more quickly than data stored elsewhere. Therefore, the more cache RAM each component has, the faster it will be able to manipulate data.

- A computer’s main memory is another important consideration. The more components and software have to access data directly from storage devices such as hard disks, and the more they have to wait for main memory to be freed, the slower the computer will perform tasks. Therefore, the amount of main memory fitted in a computer will have a significant effect on its performance. In fact, one of the easiest and cheapest ways to improve a computers performance is to expand the RAM memory to it's maximum.

Speed continued

Important Points
- Modern graphics cards often have new design features and more built in RAM than older ones. These graphics cards enable computers to run graphics-orientated software more quickly and smoothly.

- Some types of hard disk are faster than others. Many newer models include design features which reduce the time taken to access or move data on the disk.

- Using a faster CD-ROM or DVD-ROM drive reduces the time taken to read or copy data from CD-ROMs or DVD-ROMs. For example, a 48x speed drive is faster then a 24x drive for a given type of disk.

Capacity

As well as speed, the storage capacity of a computer is also important.
- Computers usually store most of the files that make up programs and data on a hard disk. The larger the storage capacity of the disk, the more programs and data can be stored. Once the disk is full, no more programs or data can be added.

- A computer used for simple tasks such as word processing and e-mail would not usually need a very large storage capacity. A computer that is, for example, used for working with advanced multimedia software would require more storage space for programs and files.

- Computers often use a small amount of hard disk space to supplement their main memory, i.e. to store data that is currently in use. If the amount of free (or unused) space on the hard disk becomes low, supplementing the main memory in this way can become much less efficient. Therefore the capacity of the hard disk (or more precisely, the free space available on it) can also affect the computer’s performance.

Other factors

- As described in the Speed and Capacity sections, there are many factors which impact on the performance of a computer. The speed and type of CPU is among the most important, however there are many more factors which affect it, but none more so than the application you are running.

- There would be no point in having a high end 3D graphics card with a huge amount of video RAM when all you need to display on your screen is Microsoft Word. The extra expense of such a peripheral would be unjustifiable as the computer would not utilise the specific performance gains offered by the card

- The amount of RAM you have in your computer greatly affects the speed at which it can run. Repetitive tasks are often held in RAM so they can be fetched quicker than from the hard disk. If there are more tasks for your computer to do than the RAM can store, the computer has to wait for these tasks to be fetched off the hard disk — which although very fast, is nowhere near as fast as RAM.

Performance question

Match the following performance statements...

- Well done!
- Sorry :-(
- If there is not enough memory...
Feedback: the computer may slow down as more programs are used.
- A CD ROM that is 48x speed...
Feedback: is twice as fast as a 24x speed.
- A slow graphics card...
Feedback: may affect computer performance.
- If the space on a hard drive is nearly full...
Feedback: the reading and writing may slow the computer.