1. Nat 4/5 Computing Science Types of Computer and Performance
Computer Systems
Nat 4/5 Computing Science
Types of Computer and Performance

2. Lesson Aims By the end of this lesson:
Nat 4/5
Lesson Aims
By the end of this lesson:
Pupils at Nat 4 level will be able to:
Describe and use clock speed as an indicator of performance
Pupils aiming for Nat 5 will be able to
Describe the uses of embedded, smartphone, laptop, desktop and supercomputers.
Compare features of embedded, smartphone, laptop, desktop and mainframe computers:
Discuss the type and speed of processors

3. Clock Speed Clock speed is the simplest measure of performance
Nat 4/5
Clock Speed
Clock speed is the simplest measure of performance
This is the amount of operations that the computer can perform in one second
Modern home CPU’s operate in the GHz range
This means at least 2,400,000,000 instructions per second

4. Speed isn't everything Some processors have 2, four or six cores
Nat 4/5
Speed isn't everything
Some processors have 2, four or six cores
2,3,4,6, 8 or 16 cores are the usual options
This means that there are 2, 4 or 6 smaller processors built into a single processor.
Each core can work on a single instruction
The faster the processor the more heat they generate.
If processors overheat they stop working
So which is better?
Dual core at 3.5Ghz or Quad core at 2.4Ghz?

5. Nat 4/5
Sometimes power is key
Other processors might need a very low power usage
For example using in netbooks, mobile phones or other portable devices.

6. Nat 4/5
Apples and Oranges
When comparing performance it helps if the processors are of similar type etc.
For example you cannot compare the clock speed of a Dual Core processor to that of a Quad core processor.
The fastest supercomputer only has a clock speed of 1.6 Ghz (but it does have1,572,864 of them!)
1.6 Pb of RAM might help too!
Sequoia billion people on earth using calculators and working together on a calculation 24 hours per day, 365 days a year, for 320 years…to do what Sequoia will do in one hour.

7. Nat 4/5
Types of Computer
As technology improves the types of computer produced change.
Social factors also change types of popular computers
For example laptop sales in the last few years have surpassed desktops.
There are an increase in smart phones
And almost every piece of equipment will have a computer ‘embedded’ inside it

8. Different Types of Computer
Nat 4/5
Different Types of Computer
Smartphone
Laptop
Desktop
Mainframe
Embedded
Supercomputer
Tablet

9. Nat 4/5
Moore's Law
In 1965 the co-founder of Intel(Gordon Moore) made a prediction that:
“The number of transistors incorporated in a chip will approximately double every 24 months.”
So far this ‘law’ has held true but there are physical limits that will be reached.
Current processors are manufactured using 32 nanometre transistors (switches)
Intel has developed transistors so small that about 200 million of them could fit on the head of a pin

10. Summary You need to be familiar with the following types of computers
Nat 4/5
Summary
You need to be familiar with the following types of computers
Embedded, laptop, desktop, supercomputer and smartphone
And compare them in terms of:
Type and speed of processor
Size of main memory
Backing storage
Input and output devices