Motherboard

A motherboard allows all the parts of your computer to receive power and communicate with one another.

The CPU

a.k.a. the process, microprocessor, or “brains of the computer”

The Central Processing Unit

• 3 parts of a CPU

o Arithmetic/logic unit (ALU) Contains the circuitry to carry

out instructions

o Control unit Sequentially accesses and

decodes program instructions Coordinates flow of data in and

out of ALU

o Register Storage within the processor

The Central Processing Unit and Random Access Memory (continued)• Were does data go between processing?

o Random access memory Temporary, or volatile, storage

• How does it get there?o System bus

Electronic pathways between the CPU and RAM

Front Side BusA front side bus (FSB) is an electrical pathway on a computer’s motherboard which connects the various hardware components to the central processing unit

(CPU).

This bus is bi-directional, meaning data can flow both ways, allowing components to send and receive data

from the CPU

Since so much data passes through the front side bus, a computer’s overall performance will be dependent, in part, on its speed. Speed depends on how wide the

bus is

ChipSets The chipset is the "glue" that connects the

microprocessor to the rest of the motherboard

It consists of two basic parts -- the northbridge and the southbridge

Northbridge:

The northbridge connects directly to the processor via the front side bus (FSB).

A memory controller is located on the northbridge, which gives the CPU fast access to the memory.

Southbridge: The southbridge is slower than the northbridge

Information from the CPU has to go through the northbridge before reaching

the southbridge

A southbridge chipset handles all of a computer's I/O functions, such as USB, audio, serial, the system BIOS

The Northbridge is located closer to the CPU than the Southbridge

PCI Slots:(Peripheral Component Interconnect) Mainly used for network and sound cards

AGP Slots: Accelerated Graphics Port

AGP video cards are capable of a higher

data transfer rate than PCI video cards.

ISA Slots: (Industry Standard Architecture)

Used as an expansion slot for peripherals

BIOS

Basic Input Output System

Gives important instructions to the

computer hardware

SATA

Serial IDE

Used to connect Optical Drives and Hard Drives to the Motherboard

The date Dec 31 1969 is the epoch date (representing this number in bits would

be all zeros)When your system resets the system

clock, it is reset to the epoch date

Current time information is not stored in a file, rather it's synced from your hardware clock with /sbin/hwclock during boot. Seeing this date, usually means, your system clock has been reset, this is often caused by a faulty battery on your

system board (a CMOS battery)

The Machine Cycle

• Execution of an instruction involves two phases: o Instruction phase, execution phaseo Two phases together make up the machine cycle

The Machine Cycle (continued)

• Instruction phaseo Step 1: Fetch instructiono Step 2: Decode instruction

• Execution Phaseo Step 3: Execute instructiono Step 4: Store results

CPU Characteristics• System clock

o Produces a series of electronic pulses at a predetermined rate called clock speed

Clock Speed -- Measured in megahertz (MHz) or gigahertz (GHz)

• Wordlengtho Number of bits that a CPU can process at once

• MIPS - Millions of instructions per secondo Amount of time it takes to execute an instruction

• Cache -- measured in MB or KBo Temporary high-speed storage areas

• FSB speed – measured in (GHz/MHz)

Cache

Multiprocessing and Parallel Processing

• Multiprocessing o Uses more than one processing unito Examples:

Parallel processing Links several microprocessors to operate in parallel

• Multi-core processingo Incorporates two or more processors on a single

chip