Computer Components Flashcards
What is CPU?
central processing unit
controls the interpretation and execution of instructions, decodes instructions and carries out the corresponding arithmetic, logic, or control operations
What is RAM?
random access memory
stores the short term data a pc requires to operate
What is SDRAM?
synchronous dynamic RAM
DDR (double data rate) (DDR2…)
faster version of RAM (used in gaming PC)
What is ROM?
read only memory
computer storage that contains non-volatile, permanent data that, normally, can only be read, not written to
What is BIOS?
basic input output system
the program a computer’s microprocessor uses to start the computer system after it is powered on, also manages data flow between the computer’s operating system (OS) and attached devices
What is PCI? What was it replaced with?
peripheral component interconnect, replaced with PCIe (peripheral component interconnect express)
connecting a computer to one or more peripheral devices
What is BUS?
the wires connecting the CPU and the other components
How does data flow between input devices, output devices, storage devices, communication devices, and the CPU?
data flows from the input devices to the CPU, data flows in both directions from storage devices and communications to the CPU, and then data flows from CPU to the output devices
Summarize Von Neumann architecture?
a computing model that is composed of a CPU, memory, and input/output devices
Are CPU replacable?
sometimes (usually desktops), often smoldered onto the motherboard
How is processing speed represented?
computation occurs in cycles, the unit is Hz which represents the number of cycles per second
How is storage space represented?
data is represented in bits, the base unit is a byte (8 bits)
How are larger magnitudes of processing speed and storage space represented?
combining them with metric or binary prefixes
ex. gigahertz, terabytes
How many bytes are in a kilobyte? What about a megabyte?
2^10 (1024 bytes)
2^20 (1048576 bytes)
What is the difference between a control bus and a data bus?
control: carries control signals from the processor to other components, also carries the clock’s pulses
data: carries the data between the processor and other components. The data bus is bidirectional
What is used to prolong cell lifespan of flash storage?
wear leveling (does this by spreading the storage of the cells equally)
Can hyper-threading make CUP do 1+ intructor in one core?
yes (executes more than one instruction at a time)
Is the CPU-RAM BUS normally narrower thatn PCIe BUS?
no its noramlly wider
Are solid state drive or hard disc drives more resistant to shock?
solid state
What is the control unit?
decodes instructions and activates the relavant components
What is the arithmetic logic unit?
instructions are applied to data, performs arithmatic, logical, and bit manipulation
What is the instruction register?
contains the instructions being executed
What is the program counter?
contains the location of the enxt instruction
What is CPU speed often called? Why?
clock speed, all operations are synced to a clock
Where is the data contained inthe CPU?
reigster file
What is main memory also known as?
DRAM or RAM
What is the main memory?
a collection of temporary storage locations each with their own address, contains volatile contents and data for currently running programs
What does volatile contents mean?
erased once powered off
What is the fetch-decode-execute cylce?
instrucitons and data stored in main memory are fetched, instructions/data is decoded in the control unit, the ALU exectues the instruction/data
Up until 2005 how many core components did the CPU have?
only 1 set (CU,ALU,registers)
Nowadays how do manufacturers design CPUs?
multiple modestly fast cores, rather than a single really fast core, or
1–2 fast cores and 6–7 power-efficient cores
How many cores do smartphones usually have? What about laptops? Desktops? Servers?
2-8
2-4
2-8
4-64
What is cache?
acts as temporary storage for recently acessed data, faster than main memory
What is turbo boost? What does it typically require?
where you increase the processing speed one or more cores, disabling other cores to ensure continued stable operation
What is hyper threading? Is it better than using two real cores?
processing two unrelated instructions at the same time in the same core
no
What is GPU?
graphics processing unit
specializes in rendering 3D graphics
How many cores can exist in a GPU? Why?
100s-1000s
do not require sophisticated computing
cores
What does bus width mean?
the number of bits that can transfer at the same time
What is the width of the CPU-RAM bus? What about the speed?
64 or more bits wide plus some additional bits for error detection, 2.4-4.8 GHz and transfer up to 20 GB/s in modern computets
What is the width of the PCI-express bus? What about the speed?
1 bit to 32 bit wide (suaully 16 bits), 2.5-8+ GHz (usually 5 or 8)
What are hard disc drives?
mechanical in nature, contains a magnetic spinning disc with a head that hovers over disc surface, fixed storage, non volatile, magnetically encoded info
What are blue ray/CD/DVD?
optical in nature, lasers read the disc, lands reflect light (binary 1), pits disperse light (binary 0), can change what is being stored on it
Do solid state or hard disc drives have a lower data access time?
solid state drives take 100 ns while hard disc takes 10ms
Can SSDs or HDDs transfer more data?
SSDs transfer 500 MB/s – 3.5 GB/s while HDDs only can transfer 150–250 MB/s
Are HHDs or SDDs more expensive?
SSDs
What does flash based storage use? How is data stored?
solid state memory chips, contains non-volatile info (retain state w/out power)
in cells, 1-5 bits per cell
What are some techniques to extending lifespan of cells?
provisiong: includes extra capacity to use when cells start to fail
wear levelling: distributing inf among cells equally
What are USB “thumb” drive, flash cards used for?
removable and portable storage, Basic performance for occasionally
reading/writing a few files
What are SSD used for?
fixed, internal storage, Improved performance for constantly reading/writing random
files, performing error checking, and securing data
What are SSHD used for?
A hard drive with some solid state flash memory for storage, All data is stored on the hard drive, but frequently accessed data is copied to the flash memory for faster access
How are the size, resolution, and density of a display monitor measured?
size is measured diagonally in inches
resolution is reported as (# of pixels wide) x (# of pixels tall)
desnity is measured in pixels per inch
How do modern displays produce an image on screen? How do they do this?
Liquid crystal display and light emitting diodes
LCD panel forms an image and LED’s provide backlight
What is twisted nematic? What is it used for?
accurate reproduction of fast moving images but colours appear distoreted when viewing from off centre angles
cheaper latops and some gaming displays
What is in plane switching?
better reproduction of colours especially from angles
used in most contemporary dispalys, especially mobile phones
What do input devices allow users to do?
provide info to the computer
What do output deivces allow computers to do?
provide info to the user
What do hybrid devices facilitate?
input and output devices
What do resistive touch screens consist of?
two transparent sheet, seperated by a gap, they have electrical charges in perpendicular directions
How do resistive touch screens work?
pressure causes the electrical charges to touch, sending a signal telling the device where the touch is
What are some advantages and disadvantages of resistive touch screens?
pros: pressure from any object will register as touch, low cost
con: vulnerable to scratch/damage
How do capacitive touch screens work?
an electric field exists on the surface of the screen, touching the screen disrupts this field and a grid of eelctrodes behind the screen detect the position of touch
What are some pros and cons of capacitive touch screens?
pro: more durable, can detect multiple touch points
con: touch is only activated by bare finger or conductive material
