clock speed
(processor speed) computers run at a pace determined by the CPU’s clock speed, internal
-measured in cycles per second (Hertz),
Primary storage
(main memory), volatile meaning that if power if turned off every stored in primary memory is lost
-made up of Random Access Memory (RAM) and cache
cache memory
name of very fast memory chips located on the central processing unit
Latency
refers to how much delay there is between when a request is made for something in RAM and when the response is available
Secondary Storage
Differs in 3 ways:
- must be loaded into primary data before accessed by CPU
- non volatile
- takes longer to access contents
2 Types: Hard-disk drives (HDDs) & Solid state Drives (SSDs)
multithreading
computer with a single core can appear to run multiple processes at once by switching back and forth among processes many times per second
-occurs when once process is broken into slices, and then slices from different processes are interleaved so quickly that it appears that multiple programs are running at the same time
time slice
to enable a single core to run multiple threads, the operating system sets up a timer, which interrupts the system at a fixed interval
-single interval is known as a time slice
hyperthreading
- allows a single processor to perform two seperate threads of computer instructions from the same computer applicatin
- each physical core is assigned two virtual cores, virtual cores are called logical cores
- each logical core is assigned a thread
- single processing task is broken into parts, and those parts assigned to threads
- parts are scheduled in the most efficient way
random access
refers to the ability to access any specific location in RAM quickly as others
Hard Disk Drives
- data is stored on multiple magnetic platters, these platters are coated with magnetic media and are mounted on a spindle that rotates the platters
- while the platter spins, an arm that contains a read/write head moves in and out across the platter to find or write data
- takes lots of time
Solid State Drives
- use no moving parts
- faster
CPU Gathering Information
- CPU looks in Cache
- Calls RAM
- If in RAM, overwrites cache memory with what was in the RAM by the amount needed to store the new instruction or data
- If not in RAM, goes to second storage
bit
smallest discrete unit of storage that can be stored
byte
8 bits make up a byte
-each byte can represent 2^8 = 256 combinations of 1’s & 0’s
word size
refers to the number of bits a computer’s CPU can process at one time
motherboard
is the board in a computer that everything else connects to
-contains internal bus, which serves as the communication highway within the computer
Information technology (IT)
is a field concerned with the use of technology in
managing and processing information.
There are two basic categories of
information technology: hardware and software
Hardware
consists of the physical
devices associated with a computer system.
Software
is the set of instructions that
the hardware executes to carry out specific tasks.
Input devices
The equipment used to capture information and commands (e.g., keyboard, scanner).
Output devices
The equipment used to see, hear, or otherwise accept the results of information processing requests (e.g., monitor, printer).
Communication devices
The equipment used to send information and receive it from one location to another (e.g., modem).
central processing unit (CPU) (or microprocessor )
is the actual hardware that interprets and executes the program (software) instructions coordinates how all the other hardware devices work together.
control unit
interprets software instructions and literally tells the other hardware devices what to do, based on the software instructions.
