1.1.2 CPU performance

What is a CPU?

Central Processing unit- processes data and instructions.

What is Clock Speed?

Measured in Hertz

Number of fetch execute decode cycles that occur per second.

measured on the pulse of an internal clock

A PC usually has a clock speed of 2-4 gigaHertz

Pros and Cons of clock speed.

Too much clock speed- faster to carry out instructions but overheats computer and shortens lifespan.

Too little clock speed- slower at carrying out cycles but longer lifespan.

What is Cache size?

Memory on the CPU that is faster than RAM but slower than registers

Stores frequently used data.

Faster than RAM.

Pros and Cons of Cache size.

Expensive.

Faster at accessing data from main memory. But is cache is too large the purpose is defeated and it takes too long to find data.

What is the Number of cores?

How many CPU or cores a computer has.

Allows for parallel processing.

Pros and Cons of the number of cores.

Higher performance- more instructions decoded at the same time.

Only works if the computer is designed to use multiple cores.

What is an embedded system?

A computer system with a dedicated function within a larger device

Usually has a single microprocessor

Pre programmed with OS system

limited input/output ability

Examples of embedded systems

Microwave, singing birthday cards, gps satnav, washing machine