THE COMPONENTS OF THE SYSTEM UNITBy: Clara Miles and Jarrick Lumma

The Motherboard The motherboard is the main circuit board of the

system unit. It can also be called a system board.

It contains places to attach to many components, such as CPU, memory, hard drive, controller, graphics card, sound card, keyboard, and mouse.

The motherboard’s most basic role is to connect the system’s microprocessor to the rest of the computer.

The Processor A processor is a logic circuitry that responds to

and processes the basic rules that drive a computer.

The processor interprets and carries out the instructions that operate a computer. It manages most of a computer’s operations.

The processor contains a control unit and an arithmetic logic unit. They work together to perform many operations with processing.

It is commonly said to be the “brain” of the computer.

The Control Unit The control unit is the component of the

processor that directs most of the operations in the computer. It plays a big role to the processor.

The control unit interprets each instruction issued by a program and then initiates the appropriate action to carry out the instruction.

The Arithmetic Logic Unit The arithmetic logic unit (ALU), is another

component of the processor. It performs arithmetic, comparison, and other operations.

Arithmetic operations include basic calculations such as addition, subtraction, multiplication, and division.

Comparison operations involve comparing one data item with another to determine whether the first item is greater than, equal to, or less than the other item.

The arithmetic logic unit is the building block of the central processing unit of a computer.

Machine Cycleo A machine cycle, also called a processor cycle or

an instruction cycle, is the basic operation performed by a central processing unit.

o It consists of a sequence of four steps. They are fetch, decode, execute, and if necessary, storing.

o For every instruction, a processor repeats those four basic operations, which comprise a machine cycle.

Registers High speed storage locations that are

located in a processor. Temporarily hold data and instructions. Are part of the processer and not

memory or a permanent storage device. Processers have many different types of

registers

How Registers Function Register functions include storing the

location from where an instruction was fetched.

Storing an instruction while the control unit decodes it.

Storing data while the ALU computes it. Storing the results of a calculation.

The System Clock A small quartz crystal unit that controls

the timing of all computer operations. It generates a regular electronic pulse, or

tick, that set the operating speed of the system unit.

Each tick equals one clock cycle. The pace of the system clock is called

clock speed. The higher the clock speed the higher the more instruction to processer can execute per second.

Measured in gigahertz.

Comparison of Personal Computer Processors

Leading processor chip manufactures for PCs: Intel, AMD, Transmeta, IBM, and Motorola.

When you compare you look at the brand, how fast the system clock is, what the core of the processor is, and if the processor is a chip.

Heat Sinks, Heat Pipes, and Liquid Cooling

Heat sink- a small ceramic or metal component with fins on it surface that absorbs and disperses heat produced by the electric components inside.

Heat Pipes- smaller than heat sink and cools processors in notebooks.

Liquid cooling- uses continuous flow of liquids, such as water and glycol, in process that transfers the heated fluid away from the processor to a radiator grill that cools the liquid and returns it to the processor.

Parallel Processing A method that uses multiple processors

simultaneously to execute one task or program.

It divides a single task into portions. Some PCs use this method with dual-core

or multicore processors. It is used by supercomputers.