it hardware Flashcards
what are the main sections of the CPU?
the Control unit(CU) and the Arithmetic Logic Unit ( ALU)
what do the ALU and CU contain?
registers
what is the function of the CU?
it controls the execution of each instruction and sends read or write signals to memory and the address of the instruction to be fetched
what is the function of the ALU?
calculations and logical comparisons take place here. Once processed data results may be sent back to memory to be stored there.
what is the accumulator?
it is a register that stores the result of each execution.
what happens when data is stored?
its written from the accumulator to RAM.
what is the function of registers?
they store the current instruction and its data
what are registers made of?
static RAM or (SRAM)
why is SRAM so fast?
they do not contain capacitors. Which have to be constantly refreshed.
How many bits are in CPU registers?
32 or 64 bits
what is the difference between 32 bit processors and 64 bit processors.
32 bit processors have to process information in two stages where as 64 bit processors do so in one stage which improves their performance.
what does paralell processing do?
a method of simultaneously breaking up and running program instructions on multiple multiprocessors.
how does parallel processing work?
Each part is broken into its individual set of instructions and each instruction on a different processor or if a user is running different programs at the same time each program can be run on its own processor
how does hyperthreading work?
by duplicating registers on the chip the next instruction is preloaded into the second set of registers while the first set of registers is being processed reducing the time it took to switch between instructions
what does hyperthreading allow for?
hyperthreading makes it appear as if two sets of instructions are being executed at the same time.
what is a set of instructions called?
A thread
what is the entire program to be processed called?
A process.
what is a process state?
All values related to the process that are stored in the registers.
where is the data of the currently executing instruction saved?
In RAM
where is the state or data of the next process loaded?
from RAM to the registers
how does hyperthreading improve performance?
it allows for fast context switching between two processes eliminating the time of loading and saving into the registers each time there is a switch between processes.
what does a hyperthreaded CPU appear as in the Operating System?
two logical CPU where in actuality there is only one physical CPU with two sets of registers.
what is the important thing to remember about hyperthreading and Operating Systems?
Hyperthreading must be supported by the Operating System.
what is multiprocessing?
It is having multiple CPU called cores on a single CPU chip.
what does multiprocessing change from hyperthreading ?
it allows for multiple processes multiple to happen at the same time instead of appearing to happen at the same time.
what must support multiprocessing for it to be effective?
it must be supported by the motherboard and the operating system.
what effects the perfomance of the CPU?
The speed of the CPU and the register size.
what is the general rule of the CPU?
It should never stay idle.
what is between the CPU and RAM
cache memory
what is cache memory made of ?
SRAM which is faster than DRAM(Dynamic RAM which is normal RAM.
what does cache do?
stores blocks of program instructions and data that have been pre- fetched from RAM in hope that these instructions or data will be needed next by the CPU.
what is level one cache ?And how fast is it?
it is a small amount of memory built into the internal circuitry of the CPU. it is usually the same speed as the CPU’s internal speed.
what is level two cache, where is it and how fast is it?
it can be located on the CPU chip it is usually half the CPU speed and it is larger than level one
what is level two cache, where is it and how fast is it?
it can be located on the CPU chip slightly further away from the internal CPU circuits, L2 is usually slightly larger and usually slower access running at about half of the CPU’s internal speed.
where is level 3 cache located and how fast is it:?
it is on the motherboard closer to the CPU and RAM. It is larger and slower access than L! and L@
In which order does the CPU check cache before it checks RAM?
L1 then L2 and then L3 and finally RAM.
how is cache incorporated on modern CPU’s?
most modern CPU’s have built in L1 and L2 caches per core and share a single L3 cache on the motheboard while other designs have the L3 on the CPU die itself.
what is a cache hit and a cache miss?
This is when the requested data can be found in a cache while a cache miss occurs when it cannot.
how are cache hits served?
when the data is read from cache.
how does cache improve performance ?
when more requests can be served from the cache .
what does RAM do?
RAM stores the programs currently in use and the data associated with them.
what does RAM
do?
RAM stores the programs currently in use and the data associated with them.
what is the most common type of RAM?
Double Data Rate SDRAM
what does each DRAM chip contain?
a capacitor.
what does SDRAM stand for?
Synchronous Dynamic Read Access Memory.
What is synchronised with the CPU and why?
the refreshing of the RAM chips is synchronised with the CPU so that the CPU does not have to wait while refreshing takes place.
why does synchronising the CPU and the refreshing of the RAM improve performance?
The CPU is working at a very high frrequency and instructions can be fed to the CPU at a fast rate reducing the length of time that the CPU is idle.
what does Double Data Rate mean?
It means that data is tranferred twice as fast as when data was transferred only once every clock pulse.
what is latency?
its the time taken for a component to respond.
what is latency measured in?
clock ticks.
what are the different levels of memory?
level 0: registers
level 1 : on chip L1 cache(SRAM)
level 2:off chip L2 cache chip (SRAM)
level 3: main memory(DRAM)
level 4 local secondary storage(local disks)
level 5: remote secondary storage ( distributed file systems, Web servers)
what is the motherboard?
it is the central printed circuit board that connects components and devices to each other.
what connect components and devices?
busses
what are the slots on the motherboard for?
to connect devices like graphic cards and hard drives.
what is a system clock?
the clock refers to a microchip that regulates the timing and speed of all computer functions.
how does a system clock work?
there is a crystal that vibrates at a specific frequency when electricity is applied.
what is the shortest time any computer component can perform at?
one clock or one vibration of the clock chip.
what is overclocking?
this is the practice of making computer components run at speeds father than designed by manipulating the frequencies at which the component is set to run .
what are the two ways overclocking can be performed?
per component which means the CPU operates faster than the system clock by changing its own manipulation factor.
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 is the danger of overclocking?
the components may run faster than the speed for which they were designed and tested causing them to become unstable or fail,
what is CPU speed measured in ?
GHz
what is RAM speed measured in?
MHz
what is the difference between speed and throughput?
speed is the maximum speed but due to latency the actual speed maybe be reduced which is called throughput.
what is and FSB?
it was initially a parallel bus that connected all components on the motherboard but point to point serial connections replaced the FSB(front side Bus) now front side buses usually connect the CPU and RAM.
what is the Data Bus?
the data bus transfers the actual instruction or data between the CPU and RAM.
what makes data buses faster?
a wider bus
what dictates register size
the number of bits that the data bus can deliver to the CPU.
what does register size indicate?
how much information the processor can operate on at one time and how it moves data around internally within the chip.
what does the addreess bus do ?
It transfers the physical address of the instruction or data between the CPU and RAM.
what does the control bus do?
it carries commands between the CPU and RAM
what is PCI Express and what is it used for?
PCI express slots are used to connect graphics cards, RAID cards, WIFI cards or SSD’s tto the motherboard.;
what is SATA and what does it do?
SATA(Serial Advanced Technology Attachment ) is a computer bus interface used to connect mass storage devices such as hard drives to a computer motherboard
what has SATA been replaced with
Parallel ATA and IDE standards
what is USB and what does it do?
Universal Serial Bus technology was designed to standardise the connection of just about any peripherals to computers both to communicate and to supply electric power.
what is non-volatile memory express and what does it do?
NVMe is computer communication bus interface that connects SSDs to the motherboard. The bus allows SSDs to read/write at a much higher speed than via a SATA communication bus.
what was M.2 Format made for?
it was designed for manufacturers to install a variety of high-speed devices that require very little power in small spaces.
what are examples of M.2 cards?
Wi-Fi and Bluetooth radios and SSDs.
how does cloud storage work?
the computer is connected to remote storage using the internet.
what is disk cache ?
It is a hardware mechanism for improving the time it takes to read from or write to a hard disk.
what is browser cache?
every time a website is accessed a copy of the website is kept in the browser cache on your local hard disk.
what does web cache do?
also known as proxy server cache stores the recently accessed webpages on a server in a network.
what is the main difference between web cache and browser cache?
while browser caches are usually private being restricted to indivivual users a web cache is a shared store of previously downloaded web pages, images etc. on a server of an organisation. if anyone on the network tries to access a site that has been previously accessed the site will be delivered from the organisatoins’ server not from the remote web server.
why is web cache convenient?
the site in the web cache may not be the latest version but loading sites from the organisation’s server is much quicker and reduces overall network traffic.
how does web cache work ?
when the first request to the web page by a user in a network will access the Internet and store a copy in the proxy server’s cache. The web page will be sent to the user’s local computer and is stored in the user’s browser cache.if someone else in the organisation requests the same web page then the request will be fulfilled by the proxy server without accessing the Internet and the web page is sent to the second user’s computer where the page is again cached on their local browser cache.
what is the difference between the onboard controller and expansion card ?
onboard is a term used to describe a hardware component embeded into a circuit board it oftens refers to a device like a sound card, network card or adapteer intergrated onto the motherboard unlike expansion cards users cannot remove these components from their computer/
what is the drawback of onboard controllers and how is it made up for ?
It contradicts the principle of modularity as they cannot be removed and replaced however if an onboard controller fails a replacement card can attached to a motherboard slot or a USB port
which is better an expansion card or an onboard controller
the expansion card that is plugged on to a slot on the motherboard will usually provide better functionality than the onboard counterpart
how does a Raspberry Pi work
on the basis that there are some onboard controllers but most of the peripherals must connect exterrnally using the USB ports
what is a co-processor
an “assistant” to the CPU by taking over the burden of some of the processing
how do the CPU and the co-processor work together
the CPU and co-processor process in paprallel speeding up data processing
what are ths most common co-processors
graphics and maths
how is a pixel represented
in 24 bits(8 red,8 green and 8 blue=RGB) and needs to be set to a certain colour to create an image which is refresehd at about 60 times per second
how are graphics processed
by the CPU or by a graphics card
what is the GPU
a co-processor that accerlerates applications running on the CPU by off loading the complex mathematical and geometric calculations necessary for graphics rendering
how does GPU optimise performance
from a user’s perspective the application runs faster because of the massive parallel processing power of the GPU boosting performance
what are the four main components of a graphics card
a motherboard connectino for data and power
a processor to render each pixel on the screen
memory to store details about each pixel and to store completed pictures temporarliy
a monitor connection to view the images
what is the most important component of the graphics card.
the GPU with many cores to process in parallel
what is VRAM
stores data about each pixel, its colour and location on the screen. faster VRAM can improve the performance of graphics card provided the GPU is sufficiently powerful.
what do modern day graphics cards use
PCI Express x 16 connector to connect to the motherboard
what do intergrated graphics serve as
more than adequate as opposed to a serparate graphics card who require more realisitcy images
what are Intergrated Graphics
instead of a separate GPU the GPU is embedded into the CPU and instead of seperate VRAM the GPU chares system RAM
what are the advantages of intergrated graphics
the cost it makes the computer or laptop more affordable and theres less head and less power user this can result in longer batter life in mobile devices
what does the Maths co-processor
it can help the ALU of the CPU process complex calculations using numberic data
what is numeric data
it is either an integer where the decimal point is fixed or a real number where the decimal point can be anywhere
what are real numbers called
floating point numbers
why are co-processors designed to perform floating point calculations extremely quickly
it co-exists with the CPU on the motherboard whenever a floating point calculation needs to be done the CPU hands the calculation to the co-processor and carries on with another task until the answer is produced
what is the acvantage of a maths co-processor
that calculations are processed faster improving performance
what are the disadvantages of a math co-processor
the cost of the additional co-processor the required motherboard space and greater power consumption of the second co-processor
the math co-processor was an optinoal add-on for earlier processors but now all processors are realesed with a math co-processor incorporated onto the CPU
what factors determine overall RAM speed
frequency affects maximum bandwidth which is how much data can trable to and from RAM at a time . Latency affects how quickly RAM can respond to a request the optimum is to have the highest possible frequency coupled with the lowest possible latency
how does virtual memory affect RAM
increasing RAM is a better optin to reduce the need for virtual memory the operating system will automatically manage the amountin of allocated virtual memory but you can change these settings
what is the data that is stored in virtual memory on your secondary storage device called
a paging file
explain internal busses
they are known as local buses because they are on the motherboard and an intergral part of the processing capailities of the computer
how does bus size impact processing speed
the larger the bus the greater tha ability to carry more data in the same amount of time
compare internal and external buses
external buses are much slower than internal buses
explain usb standards
when you buy a USB device the highest standard that the device requires will be specified meaning the cable and the device must all comply with the required USB standard for it to run at the desired specification
give a description of usb type a
the familiar rectangular port usually the host device meaning it provides exlectricity and controls the data transfers to attached device
give a description of usb type b
often used for external hard drives and printers commonly found on portable devices with mini type b being replaced by micro type b USB
give a description of usb Micro B
before type was designed to carry data and power in Usb SuperSpeed applications
give a description of type c
similar size to micro USB connections and allows charging with bidirectional power
give a description of USB On The Go
Usb OTG allows mobile devices to act as Usb hosts
what were HDMI and DisplayPort create for
quality digital video and audio signals
what is the difference between HDMI and DisplayPort
DisplayPort cables can achieve higher bandwidth than HDMI cables.
supports multiple monitors with a single cable using daisy chaining. instead of having multiple cables plugged into the source computer a multi-display setup can be created.
what are the differences between thunderbolt 3 and USB-C
SPeed thunderbolt 3 :up to 40Gb/s USB-C: Up to 10Gb/s Display Thunderbolt 3: Two 4k displays or one 5k display USB-C:one 4k display Expansion thunderbolt 3 up to 6 devices USB On-The-Go USB OTG allows mobile devices to act as USB hosts
what do HDMI and DisplayPort allow for
they carry High Definition quality digital video and audio signals
why are DisplayPort cables better than HDMI
DisplayPort cables can achieve higher bandwidth than HDMI cables
DisplayPort supports multiple monitors with a single cable by using daisy chaining.
what is daisy chaining
A user can plug one DisplayPort cable into a monitor link the first monitor to the second monitor using a DisplayPort cable and then a third monitor is linked to the secnod monitor and so on
what is the disadvantage of a multi-display setup
the monitors need to support this feature and it is usually found on high-end monitors
what is the difference between THunderbolt 3 and USB-C
THunderbolt 3 : speed= up to 40Gb/s display=Two 4K displays or one 5k display Device compatibility= USB-C devices Legacy USB s.x/2.x devices using adpater with speed limited to device capabilities Expansion= Daisy-chain up to 6 devices USB-C: speed = Up to 10GB/s display =One 4k Display Device Compatibility= USB-C devices Legacy USB s.x/2.x devices using adapter with speed limited to device capabilities Expansion =can only connect one device
why is secondary storage important
At the high-end of processing a faster HDD or SSd will signigicantly improve the ability of the processing components to access the data on secondary storage as quickly as possible
give a comparison of SSD VS HDD
SSDs have no moving mechanical components
HDDS contain spinning disks and movable read/write heads
compared with electromechanical drives SSDs are typically more resistant to physical shock, sun silently, have quicker access time and lower latency
SSDs are still more expensive per unit of storage than HDDs
SSDs take around three times less boot up time than HDDs
SSDs consume less power also averagingn about three times less thatn that of an HDD
what is M.2
It is a form factor it describes the shape and size of a hardware device. The M.2 connector can access the PCI-express 3.0 SATA 3.0 and USB 3.0 bus depending on the type of M.2 device/
what are M.2 SSDs
they are small drives connected directly to an M.2 socket on the motherboard as opposed to SATA based drives that use cables to connect to the motherboard and provide power.
what does the innovative lack of cables make M.2 drives ideal for
Small Form Factor(SFF) systems that have little room for cable routing.
what are the two main type of M.2 SSDs
the first uses the PCIe bus and those that use the SATA bus
what is the difference between SATA and M.2
they are both SSds but with different sizes and connectors.M.2 is a small form fact and SATA is a bus tupe. SATA SSDs come in two form facts.M.2 has SSDs has the same performance as their 2.5 inch counterparts and plug directly into the motherboard eliminating the need for cables
what is NVMe
Non-Volatile Memory express
how does NVMe connect
it connects via PCI-Express
what do NVMe SSDs produce
a significant increase in speed over SATA SSDs by upgrading a mechnical hard drive to an SSD increases performance in tasks from boot speeds to file load speeds however upgrading to an NVME SSD will produce even more significant performance gains.
how do you achieve higher speeds from NVMe SSD
to achieve these speeds from your NVMe SSD make sure your NVMe SSD make sure your operating system is installed on the SSd drive together with frequently used programs games and data
explain SATA SSDs
SATA is an older technology found in desktop and laptop PCs. SATA drives require a SATA power cable as well as a separate SATA data cable unlesss you are using an M.2 SATA based SSD
what are common SATA devices
they include 2.5 inch SSDs, 3,5 inch mechanical hard drives and 5.25 inch optical /Blu-ray drives
laptop or Desktop PC (entry level )example specifications
Caleron processor (2 to 2.6 GHz); 4GB RAM; 500 GB hard Drive; HD Graphics card
laptop or Desktop PC(mid-level ) example specs
I3(usually 2 cores may be 4)
2 to 3 GHz Processor;4,6 or 8GB RAM; 1TB HDD or up to 512GB SSD; UHd graphics card
Laptop or Desktop PC (high level)
I5(4 to 6 cores);
2.4 to 3.4 GHz Processor; 8GB RAM ; 1 to 2TB
HDD to 256 to 480 GB SSD; GPU
I7(4 to 8cores); 3.2 GHz Processor; 8 GB RAM; 1 to 2 TB
HDD to 480GB SSD; GPU
server computer example specifications
a server is a powerful computer that provides “services to other computers in a network such as sharing data or performing computations Servers .Servers are also used as Domain Controllers for users and devices/ To work with multiple clients simultaniously the processing speed cache and RAM need to be very high. Very large secondary storage is required
what is the purpose of wearable technology
smart wear are wron near to or on the skin their purpose is to detect analyse and transmt information about the user such as vital signs and environmental data which can provide immediate biological feedback to the user
explain smart watches
smart watches are worn like a regular wristwatch and connect to a user’s smartphone via BlueTooth to notify them about phone calls, text messages emails and social media. Many can provice health and fitness data by monitoring and tracking the user’s heart rate record the number of stped taken daily and the number of calories burned
explain smart clothing
are any technologically enhanced clothing items that add funtionality beyoung that of the traditional use. some have interwoven or printed circuitry in the textiles or use sensors, haptics and extra hardware to provide smart functionality
what are Head-Mounted Displays
A Head-Mounted Display is worn on the head or is embedded in a helmet with a small display for one or both eyes and is used in gaming, aviation,engineering and medicine.
what is Augmented Reality
it creates and effect of digital content interaction with the world by overlaying projected images on top of a pair of see-through glasses
what is Virtual Reality
increases user participation bringing the user into a complete different virtual world
what are immplatntable smart devices
Implatntable smart devices are surgically implanted below the skin and carried with a person wherever they go
what does a single screen mean
that the app should be self-sufficient the task performed by the user should be easy to complete in a sigle app or on a single website users should not need to leave an app to find information that the app needs but does not provide
what do touchscreen give users
an alternate User Interface that can make the interation with the device more flud and efficient
what is a problem with touch screen
the most significant problem of a touch screen is related to typing on a soft keyboard, users need to continuously focus on the content they are typing and the kepad area. keypads are small and key are crowded
what is a CPU chip designed for and how are they created and describe them
portable devices the CPU is housed in a smaller chip package and generates less heat. It uses lower voltages and can be throttled down to different power levels of sections of the chip can be turned off entirely when not in use.
what affects battery life in mobile devices
the size of the screen, the brightness of the screen and the resolution of the screen are factors that affect the battery life connections like Bluetooth, Wi-Fi, locations and data drain battery weak signal as well
how are mobile devices energy efficient
they are designed to run on a battery for a long period of time the most power intensive tasks are the display, the processor, maintaining the connections location services and writing to memory
