10 Flashcards
Hardware
Refers to the physical components of a computer
- CPU
- System Unit and Motherboard
- Storage Devices
- Input Devices
- Output Devices
- Communication Devices
CPU (Central Processing Unit)
-“Brain” of the computer
-Housed on the motherboard in the system unit
-Processes commands (from software)
-Controls functions performed by other components
-Two main parts
=Control Unit - executes instructions
=Arithmetic Logic Unit (ALU) - performs calculations
-Arithmetic calculations (addition, subtraction, etc.)
-Logical calculations (comparisons)
Instruction Cycle
- Sequence a CPU (Control Unit) goes through to execute a command:
Fetch - retrieves instruction from RAM/cache
Decode - determines what the instruction is
Execute - performs commands
Store - store any result to RAM
-Repeat for the next command, then the next, etc.
CPU Performance
-Clock Speed: The speed at which a processor executes the instruction cycle
-Gigahertz (GHz) - 1 billion cycles per second
-Megahertz (MHz) - 1 million cycles per second
Multiple Processors
Multi-Core Processors
-Two or more processors integrated on a single chip
-Increases processing speed over a single-core processor
-Reduces energy consumption over multiple separate processors
-Dual-core (2 processors) and quad-core (4 processors) common on personal computers
GPU (Graphics Processing Unit)
-Reduces processing required of the system CPU for graphics-intensive processes
-Found on a video card
Parallel Processing
-Distributes processing across multiple processors
-Typically each process (program) is assigned to a processor by the Operating System
-Can be simulated: hyper-threading:
Intel processors
Single CPU appears as two logical processors
Pipelining
-Used to improve performance of a single processor
-Similar to an assembly line in a factory
-Allows a single processor to process up to 4 instructions at the same time
=After instruction 1 is moved from the fetch stage to the decode stage, instruction 2 is fetched, and so on
Cooling System
-Electronic components, especially processors, generate heat
-Need to be kept cool to prevent them from burning out
=Heat sink - metal used to draw heat away from CPU
=Liquid cooling system
=Cooling fans (desktops only)
=USB-powered cooling pad for notebooks
System Unit / Motherboard
-System Unit - case that encloses and protects a computer’s internal components
-Motherboard - main circuit board of a computer; provides a way for devices to connect to a computer
=CPU
=Ports - used to connect peripheral devices directly
=Expansion slots - plug in expansion cards into them (desktops only)
=BIOS - instructions for booting computer
=Drive controllers - for connecting internal hard drives
=Memory - chips for temporary storage
=Data buses - wires that allow information flow
Ports
-Used to connect peripheral devices to the motherboard
-USB - most common type of port, can connect many types of devices (such as printers, mice, keyboards, digital cameras, mobile devices, and external drives)
Can connect up to 127 devices to a single port (USB hubs)
=Can provide power to devices
=Hot-swappable - devices can be plugged and unplugged without turning off computer
=Current version: USB 3.2 using USB-C connectors
-Thunderbolt
=Can connect many types of peripheral devices
=Thunderbolt 2 is the standard on most Apple computers
=About the same speed as USB 3.2 (USB-C ports)
=Can connect up to six devices using one port
=Hot-swappable
