System Technology Flashcards
Hardware and Software
- Hardware is the physical components that a computer requires to function
- Software is a series of instructions that tell a computer what to do
ICT System
- Combination of hardware, software and people that use them
Data and Information
- Data is raw, unprocessed facts
- Information is data that has been processed and is meaningful
System Types
- PC, laptop, Arduino, Raspberry Pi, tablet, smartphones, smart wear, etc.
System Software
- Programs that run computer hardware and application programs which includes OS’s and application software
OS Functions
- Provides UI, manages resources, interface between hardware and applications and loads and runs programs
Types of OS/Software (5)
- Desktop: Linux, Mac, Windows
- Mobile OS: Android, iOS
- Embedded: Specialised OS designed for a specific task for a device that isn’t a computer e.g. microwave, dishwasher
- Utilities: Software that adds functionality to computer and increases performance e.g. troubleshooting, anti-virus
- Drivers: Allows communication between hardware connected to the computer and the OS e.g. printers, USB drives,
Application Software (3)
Programs or groups of programs designed for end-users
- Stand alone: Runs locally on devices and doesn’t need anything else to be functional
- Network: Provides communication to another app running on a different host e.g. file transfer or emails
Northbridge and Southbridge (5 + 4)
- NB: Tasks that require the highest performance: CPU CU ALU RAM/Registers Graphics Card
- SB: Components that don’t require fast processing
IO Hub
BIOS
CMOS memory
CPU Design (3)
CPU:
CU - Directs operation of the processor and tells the ALU and IO devices instructions to execute
ALU - A circuit that performs arithmetic and bitwise operations on integers
Registers - Holds instructions, storage addresses or data during the machine cycle
64 vs 32-bit processor
- 32 has 2^32 memory addresses = 4GB of memory
- 64 has 2^64 memory addresses = 16 billion GB hence can hold more sets and run faster
32 vs 64 bits of data transmitted every clock cycle
64 bit is more expensive
Machine Cycle
- Fetch the instruction from the instruction register
- Decode the instruction
- Execute the instruction
- Store the result in memory
Parallel Processing
Running two or more processes to handle separate parts of an overall task. Processes are run simultaneously on multiple processors
Hyperthreading
The splitting of physical cores into virtual cores called threads that allow each core to do two things simultaneously thereby increasing processor efficiency.
Multiprocessing
The use of two or more cores on a CPU which increases efficiency and several programs can run simultaneously on different cores.
Primary Memory (5)
Register: Holds an instruction
RAM: Volatile main memory in chips attached to motherboard in DIMM slots. Stores programs in use and data associated with them
- ROM: Chip that stores firmware and cannot be written to
- BIOS: Checks that essential hardware is present and loads the OS for the user
- UEFI: New BIOS that has a GUI and helps stop malware
Secondary Memory
HDD: Stores data by writing to a spinning metal disc with an arm. Non-volatile
SSD: Uses current to store information electronically. Much faster than HDD but is more expensive per unit of storage. OS and essential programs are loaded there while others are on HDD.
Uses the PCI-Express bus
EEPROM: Used in memory cards, USB
Virtual Memory
Using an area on the HDD to extend the RAM. Pages are swapped in and out of memory wherever an application requires memory. Slows down performance
- Paging: computer stores and retrieves data from secondary storage for use in main memory.
- Thrashing occurs when the VM is overused which slows down speed.
Cache (4)
Stores instructions likely to be needed by the CPU for faster processing times.
CPU Cache: Reduces average time of accessing data from main memory
Disk Cache: Improves the time it takes to read or write to HDD
Browser Cache: Stores pieces of frequently visited pages so that they load faster
Proxy Cache: Feature of proxy servers that stores content on the server itself
SRAM
Cache is made of SRAM chips
CPU and RAM
CPU > RAM
Faster RAM means memory transfers are faster meaning the faster processor can run at faster rates which makes the computer more efficient
Bottlenecking occurs when a component is too fast or slow and affects the speeds of other components
Latency
Time taken between request for instruction and instruction being delivered to CPU
IRQ
Signal sent to CPU to indicate that a device or process needs the attention of the CPU
POST
Diagnostic test that checks that the BIOS systems run
System clock
A small quartz crystal that vibrates at a regular frequency measured in GHz which coordinates activities on the motherboard
Overclocking increases the frequency at which components run which increases performance. Can also be done by increasing the clock multiplier value.
Clock multiplier - Sets ratio of internal CPU rate to system clock
Buses (4)
Sets of wires that transport data, instructions of addresses between components
- FSB connects CPU to Northbridge
- Address Bus connects address of instructions or data between CPU and RAM
- Data Bus transfers actual instruction or data between CPU and RAM. Number of bits of data bus dictates register size on CPU
- Control Bus carries commands between the CPU and RAM
Languages (4)
High levels are easy to learn and allow for abstraction e.g. Java
Low levels are harder to learn and are slower e.g. machine language
Compilers translate high-level source code into object code
Interpreters read and execute directly without compilation.
Code
Source code lists commands to be compiled into an executable computer program
Executable code is a program that will run as soon as it opens
Increasing Cache Size
- L1, L2, L3 (increasing order of size, decreasing order of speed)
- Expensive method of improving the ability to load instructions to CPU
Increasing RAM speed and size
- More program instructions can be loaded faster
- Less swapping of instructions in and out of memory
- Hence overall speed increases
Task-Specific Components
- Video card for 3D rendering (convert 3D graphics into 2D representations for computer)
- Faster HDD or SSD for video editing (load files faster)
- Decrease time taken to perform these tasks
Modular Design
- Breaks a system down into independent parts that can be upgraded and swapped out without having to replace the entire computer.
Adv: Upgrade components independently
Reduced cost of repair
Dis: Components can bottleneck each other depending on speeds and age
Co-Processors
- Processor that supplements to function of the CPU.
- Graphics, arithmetic functions
- GPU’s have integrated RAM to increase bandwidth
IDE
Integrated Developer Environment
Allows for contextual help, error checking and code completion.
Thread vs Core
Thread - Software and is a part of a running program.
Core - Hardware component and is a virtual processor on the CPU that shares resources with other chips on the CPU
Data Flow
- From hard drive to RAM then to cache. The data that flows is the data needed by the CPU.
Virtual memory is used when RAM is too full and parts of instruction are swapped between RAM and HDD as needed.
Cache is used to improve CPU speed as important data is found closer to CPU.
