Unit 3 Hardware Flashcards
What is hardware categorised into
Input, storage, processing, output and communication
What does IPO stand for
Input processing and output
What is the motherboard
The large printed circuit board that houses essential electronic components of a device. The central processing unit, primary memory and connectors between then and other peripherals are all linked on the printed circuit
What is the biggest chip on the motherboard
The CPU
What does the CPU consist of
- The arithmetic logic unit
- the control unit which is connected to to the control bus
- registers including the memory data register which is connected to the data bus and the memory address register that is connected to the address bus
And an electronic clock which sends clock pulses
What does ALU stand for
The arithmetic logic unit
What does CU stand for
The control unit
What is the arithmetic logic unit
An electronic circuit, made up of combinations of logic gates, that perform simple arithmetic on integer binary numbers. It can only add numbers. It also performs all logic calculations— it determines wether a condition will be evaluated as true or false
How can the ALU perform all arithmetic even when it only adds numbers
This is because subtract Is addition of a negative number and multiplication is simply repeated addition and div is ion is repeated subtraction and exponentiation is repeated multiplication so it all boils down to addition of some sort
What is the Control unit of the CPU
This is the co-ordination of the program instructions sent to the CPU. It controls instructions to be processed by the CPU. Some form of processing cycle that what the CPU does and how the instructions need to be processed in terms of ALU,RAM and input/output
Draw diagram of how CPU works
RAM and ROM send data to register while the CPU is working with it. The CU manages and coordinates the CPU and sends the information to the register then the ALU performs calculations and sends it to the register. The register then sends an output to RAM
What is a register
Small memory holding placed where instructions that are processed by the CPU are stored it is made from static RAM
What is BIOS
Non-volatile firmware used to initialise hardware when the computer starts up so that the operating system can take over and use the hardware afterwards
What is firmware
Software that is programmed on a ROM chip
What does volatile mean
Loses data when powered off
What does non-volatile mean
Keeps data stored even if not powered
What type of storage is RAM and other storage on the motherboard
Primary storage
What are the characteristics of primary storage
It is volatile
What is the characteristic of secondary storage
It is non-volatile
What are peripherals
Devices that are not places directly on the motherboard, they connect through a port
What does DRAM stand for
Dynamic Random Access Memory
Why is RAM dynamic RAM
Because it contains a capacitor which loses its charge and constantly needs to be refreshed otherwise it will lose its contents
What does RAM look like
It comes in long printed circuit boards that can be clipped onto the motherboard.
What does the CPU look like
It is square with pins that can be inserted into the motherboard in a circuit
What do you need to do to improve the speed of your computed
Add more RAM
What does ROM stand for
Read only memory
What is ROM
a Non-volatile memory chip that can be used to permanently store data in computers and other electronic firmware such as BIOS firmware, embedded operating systems and appliance/robotics controllers
Can ROM data be changed
Sometimes it not at all depending on the type of chip and it’s purpose
What does EEPROM stand for
Electronically erasable programmable ROM
What is the difference between components and peripherals
Components are generally things found on the motherboard while peripherals are things connected to the motherboard but not placed directly on it
What is removable media
When secondary storage can be removed
What does media mean
Data is stored upon
What are examples of removable media
External hard drives, flash drives, CDS and SD cards
What is a kernel
An operating system loaded into RAM it is responsible for input/output requests from software, translating them into instructions for the CPU. It handles memory and peripherals like keyboards, monitors, printers and speakers
Where are hard drives housed
Inside the computer case
What do hard drives do
They store all the users programs and days permanently
What are the different types of hard drives
Mechanical hard disk drives, solid state drives, hybrid drives, optical drives and flash drives
What does HDD stand for
hard disk drive
What does SDD stand for
Solid state drive
What are the characteristics of a hard disk drive
- Designed with mechanical parts that include a read/write head that scans the disk for data that is represented magnetically
- the vacuum is sealed and stores the data magnetically; this ensures that the data is not lost after you turn off your computer
What are the characteristics of a solid state drive
- don’t have any moving mechanical parts
- fast and less susceptible to shock or damage
- can be internal or external
What are hybrid flash drives
Where mechanical hard drives are joined with high speed flash memory using SDD technology on the same drive
What are the differences between hard disk and solid state drives
- Solid state drive are quicker and retrieving information
- solid state drives are more reliable
What are flash drives
SmalL, very portable storage device that used solid state technology with no moving parts, only electronic circuits. They connect conveniently, using a USB port.
What is an optical drive.
They use light to etch data onto the disc for reading and writing
What are examples of optical drives
CDs, DVD, Blu-Ray
What does SD card stand for
Secure Digital card
What are SD cards
They are very small flash memory cards that provide high memory for small size
Which devices use SD card AC
Digital video, camcorders, tablets, audio players and mobile phone
How much storage do SD cards provide
16G and upwards
What are input devices
A hardware device that is used to get data into the computer, this data is stored in RAM
What is the layout of the most common keyboard
QWERTY
What mouses use to detect movement
A light emitting diode (LED)
What is the accumulator
The register that stores the result of each execution.
What are the two types of registers than can be found in the CPU
32-bit and 64-bit. 32-bit processes 64-bit data in two stages
What is serial processing
when a problem is broken down into a set of instructions that are executed sequentially (once at a time)
What is parallel processing
when a problem is broken up into a set of instructions that are executed on multiple microprocessors (more than one task at a time)
Why would one prefer parallel processing over serial processing
-there are multiple processors
-higher performance
-workload per processor is lower
-requires less time to complete the task
What is hyper threading
duplicating the registers on a CPU chip. This allows for an instruction to be preloaded while one is being executed, thus reducing the time to switch between instructions.
What is multiprocessing
having multiple CPUs (called cores) on a single CPU chip.
Why do we use processor cache
the RAM is slower than the processor leaving the CPU running pointlessly which is inefficient, the cache is the easiest solution for quickly retrieving data to optimise the use of the CPU
What data does cache store
a copy of data stored somewhere else or the result of a computation previously performed
What is cache
Cache stored data so that future requests for that data can be served faster.
What is the difference between RAM and a processor
RAM:
- Measured in Size, type and access speed
- Acts as a storage for information
- handles opened programs
- less expensive
Processor:
- Measured in Clock speed, cores and cache
- acts as the brain of the system
- opens programs
- more expensive
Where does cache memory exist
Between the CPU and RAM
How many levels of cache memory are there
There are three levels, sometimes (very rarely) four and they are abbreviated to L1, L2 and L3
What is cache memory
Memory that stores blocks of program instructions and data that have been pre-fetched from RAM in the hope that these instructions or data will be needed next by the CPU. Cache memory is made up of SRAM(Static RAM) chips on two or more levels (in two or more locations)
What is level 1 cache
A very small amount of memory built in with the internal circuitry of the CPU chip. L1 cache usually had the same speed as the CPUs internal speed
What is level 2 cache
Level 2 cache is slightly larger but slower. It generally runs at about half the speed of level 1 cache and is located on the CPU, but further out than the level 1 cache.
What is level 3 cache
Level 3 cache is not always found in a computer but is still very common. It is located on the motherboard, rather than the CPU, but is closer to the CPU than the RAM. Sometimes level 3 cache is used by multiple cores that share it
In what order does the CPU look for data in cache memory
The CPU, when looking for data, will first check level 1 cache, then level 2, then level 3, and only then access the RAM if the data cannot be found in the cache
What is a cache hit
When requested data can be found in cache which is read faster than it would be accessing the RAM
What is a cache miss
When requested data cannot be found in cache
What does DDR SDRAM stand for
Double Data Rate Synchronous Dynamic Random Access Memory
What is DDR SDRAM
a type of random-access memory module that allows for higher transfer rates and faster performance compared to earlier RAM modules
What is DDR SDRAM synchronous
it’s refresh times are synced with CPU
What does the double data rate in DDR SDRAM mean
Means that the data is transferred twice as fast (twice every clock pulse on the rise and fall of the clock pulse) as when data was transferred only once every clock pulse.
What is latency
The time taken for a component to respond.
How does the latency of cache levels differ
The higher the level the lower the latency therefore the more efficient it is
What is the hierarchy of memory and cache
L0: registers
L1: L1 cache (SRAM)
L2: L2 cache (SRAM)
L3: main memory (DRAM)
L4: local secondary storage (local disks)
L5: remote secondary storage (distributed file systems, web servers)
Each memory level stores data retrieved from the previous level of memory
As you go up the memory becomes smaller, faster and costlier per byte
As you go down the memory becomes larger, slower and cheaper per byte
What synchronises all computer functions
A clock generator
What is the system clock
A microchip that regulates the timing and speed of all computer functions. Within this chip there is a crystal that vibrates at a specific frequency when the electricity is applied.
What is the shortest time any computer can perform
One clock, or one vibration of the clock chip
What is overclocking
The practise of making the computers components run at a faster speed than designed by manipulating the frequencies at which the component is set to run
What are the two ways overclocking can be done
Per component (clock multiplication factor) or by the whole system (system clock)
What is overclocking per component
The CPU operates faster than the system clock by changing its own clock multiplication factor
What is overclocking by the whole system
The system clock is increased affecting all components that detect the system clock and multiply by a factor
What is clock multiplication
Increasing the clock multiplier
What are the dangers of overclocking
- Components run at a faster speed than they were designated causing them to be unstable or fail.
- increase power consumption
- generates more heat
What cooking methods exist to compensate for overclocking
Fans, liquid cooling and heat sinks
What is speed vs throughput
Each company is described by a certain speed (theoretical speed) . Due to latency and other factors the actual speed (throughput) of the data may be reduced.
What is the speed of a bus measured in
Mbps (mégabites her second)
What is speed referred to as
Bandwidth
What does FSB stand for
Front side bus
What is the FSB (internal bus)
Initially a parallel bus that connected all the components on the motherboard. Since then point to point serial connections replaced the FSB in other connections (SATA, PCI, Express and DMI)
Where does the FSB connect
To the CPU and RAM
What is a bus
a communication system that transfers data between components inside a computer or between computers
What does the FSB consist of
The data, address, and control bus
What is the data bus
The data bus transfers the actual instructions between the CPU and RAM
What happens the wider a data bus is
It’s like having a highway with more lanes which enables greater throughputs.
What does the number of bits the data bus can deliver to the CPU dictate
The size of the registers on the CPU.
What is the address bus
The address bus transfers the physical address of the instruction or data between the CPU and RAM.
What does the width of the address bus determine
The amount of memory a system can address. Eg a memory with a 32 but address bus can address 2^32 memory locations.
What is the control bus
The control bus carries commands between the CPU and RAM
What does PCI express stand for
Peripheral component interconnected express
What is the PCI express
Slots used to connect graphics cards, RAID cards, WIFI cards or SSDs to the motherboard
What does SATA stand for
Serial advanced technology attachment
What is SATA
A computer bus interface used to connect mass storage devices such as hard drives to a computer motherboard
How many generations of SATA are there
Three, each generation the throughput is doubled from 150MB/s
What does USB stand for
Universal Serial Bus
What does NVMe stand for
Non-volatile memory express
What is NVMe
A computer communication bus interface that connects SSDs to the motherboard. Allows SSDs to read/write at a much higher speed than via SATA
What is the M2 format
With the increase in speed of SSDs and the decrease in size the SATA interface was becoming too slow and bulky. The M2 format is designed for manufacturers to install a variety of high speed devices that require very little power in small spaces. M2 cards include WIFI and Bluetooth radios and SSDs. The M2 slots can use any communications buses: SATA 3.0, PCI Express 3.0, USB 3.0, and NVMe
What is the function of the USB bus
It was designed to standardise the connection of just about any peripherals to computers, both to communicate and supply electric power.
What is cloud storage
Remote storage accessed via the internet
What are examples of cloud storage providers
Google drive and Dropbox
What is the speed of cloud storage
Because the data is transferred between your computer and a service providers service over the internet, the issue of speed is primarily determined by the speed of your internet connection.
What are the costs associated with cloud storage
The cost is two fold: there is a cost for the actual storage and there’s a cost for your bandwidth (if it applied)
What are the other types of caching other than to the CPU
Disk cache, browser cache and web cache
What is disk cache
Hardware mechanism for improving the time it takes to read, form or write to a hard disk.
Where is disk cache stored
It is integrated in the hard disk or can also be stored in RAM
What is browsers cache
cache that stores all the downloaded files from the web [such as Web page. images, music, videos and all cookies]
What is web cache
Also called a Proxy server cache Stores the recently accessed web pages on a server in a network. Loading sites from web cache is much quicker and reduces overall network traffic
Explain the process of web pages being cached
First the request to the web page by a user in the network will access the internet and a copy of the web page will be stored in the proxy servers cache. The web page will then be sent to the users local computer and is stored in the users browser cache. If someone else in the organisation requests the same web page, the request will be fulfilled by the proxy server without accessing the internet and the web page us sent to the second users computer where the page is again cached on their local browser cache.
