Computer Systems 1 Fundamentals of Computing

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Computer Systems 1Fundamentals of Computing

• Performance, Data Jargon

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Performance, Data Jargon

• Performance Terms
• Operational
• CPU Specific
• Data Representation
• Analogue Vs Digital
• ASCII
• Unicode
• Data Reduction
• Jargon
• Deciphering some computing terminology

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Performance Terms

• FLOPS
• FLoating Point Operations Per Second
• How many fractional calculations can processor
  carry out?
• Processors often have a FPU (Floating Point Unit)
  designed to do these calculations
• Improve number intensive tasks
• Such as graphics rendering
• Also called maths-coprocessor
• Another way to measure processor speed
• MFLOPS MegaFLOPS (MillionFLOPS /s)
• GFLOPS GigaFLOPS (BillionFLOPS /s)
• Thought to be inaccurate
• Some operations can take longer than others

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Performance Terms

• Benchmark
• The measuring stick against which something is
  measured
• Tests which have been devised to measure a
  specific type of equipment or program
• Used to measure and compare performance of
  computer software of hardware
• Overclock(ing)
• Processes happen in sync with clock cycle
• Theory Quicker Clock Quicker Computer
• Forcing a CPU to run faster than its approved
  and tested speed
• Used to force a little more power out of the
  processor
• Risks attached
• Overheating of CPU
• Processing errors

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CPU Types / Performance

• CISC
• Complex Instruction Set Computer
• Supports up to 200 instructions
• Instructions for complex operations
• Original Pentium processors x86
• RISC
• Reduced Instruction Set Computer
• Less instructions than CISC
• Less Instructions Faster (?)
• Cheaper to produce
• Puts bigger burden on software (?)
• Motorola processors found in Apple computers
• Pentium 2, 3 4 Use CRISC
• Combination of CISC RISC

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CPU Performance

• Pipelining
• Technique used in modern processors
• CPU fetches next instruction while processing
  current instruction
• A bit like a factory assembly line
• Pipeline split into segments
• Each segment executes a specific function in sync
  with other segments then data is moved along
• Sync is produce by clock cycle
• Pipeline Segments
• Fetch
• Decode
• Execute
• Can reduce bottleneck restrictions

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CPU Performance

• Pipelining
• Example
• Four instructions to carry out
• 1, 2, 3 4
• Pipeline Segments
• Fetch (F), Decode (D), Execute (E)

Clock Cycle
F(1)
F(2) D(1)
F(3) D(2) E(1)
F(4) D(3) E(2)
D(4) E(3)
E(4)
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CPU Performance

• Hyper-Threading
• Hyper-Threading Technology (HT Technology) is a
  groundbreaking technology that enables a
  processor to execute two threads in parallel
  allowing you and your software to multi-task more
  effectively than ever before. (Intel)

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CPU Performance

• Hyper-Threading
• Based on the Simultaneous Multi-Threading (SMT)
  method
• Parallel execution of process threads
• Allows programs to run multiple threads in
  parallel on one processor
• A Thread can be thought of as a single task that
  makes up a process
• Involves creating two logical processors
• System becomes a pretend dual-processor machine
• A logical processor can be multi-tasking
• Provides multi-tasking through time-slicing
• Is a theoretical parallel processing system
• Fools the OS into thinking there are two
  processors

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Problem Prevention / Solving

• UPS
• Un-interruptible Power Supply
• Battery backup System
• Can also perform power conditioning and surge
  protection
• Cleans power supply
• POST
• Power On Self Test
• Checks performed by the BIOS when computer is
  powered up
• Beep codes
• Also have POST diagnostic cards

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Analogue

• A continuously varying signal
• Varying in terms of frequency, amplitude, or both
• A signal that is constantly changing
• Analogue can represent many values

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Digital

• A signal with discrete value changes
• Signal levels are either on or off
• Often thought of as either 1 or 0, especially in
  computers, but digital can represent many
  different values using discrete levels

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Basic Data Representation

• ASCII
• American Standard Code for Information
  Interchange
• Represents English language characters using
  numbers (0 to 127)
• 7 bits for each character
• E.g- 115 is a small s
• Extended ASCII (uses 8 bits more characters)
• http//www.asciitable.com/

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Basic Data Representation

• Unicode
• Another standard for representing language
  characters
• Uses 16 bits for each character
• gt 65,000 unique characters
• Useful for complex languages (Greek, Japanese,
  etc.) special characters, symbols, etc.
• May ultimately replace ASCII
• www.unicode.org

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Data Reduction

• Compression
• Using an algorithm to reduce the size of a
  computer file or program
• Loss-less compression
• Information is compacted without destroying or
  removing any data from the file
• E.g- zipping a file
• Lossy compression
• Information is compacted but information deemed
  to be insignificant or redundant is thrown away
• E.g- MP3

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Jargon Busting

• AI
• Artificial Intelligence
• Attempting to make the computer behave like a
  human or think for itself
• Used in games to simulate human and random
  behaviour
• Expert systems or knowledge bases allow decisions
  or recommendations to be given based on input
• Meta
• Information about information
• Thing of Meta as meaning about
• Meta-data data about data
• Meta-language a language about a language

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Jargon Busting

• HCI
• Human Computer Interaction
• How the user and computer communicate and
  interact with each other
• Make interaction faster, easier and better
• Many different forms of interaction
• Haptic movement, gestures, physical interaction
• Auditory using sounds to interact
• Pervasive Computing
• Ubiquitous Computing
• Integration of computing technology to everyday
  life
• Introducing technology into everyday ordinary
  objects
• Allowing everything to be networked and live

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CS1 Week 9

• What you know now
• Performance
• Hyper-threading
• Pipelining
• Problem solving
• Data Representation
• Analogue Vs Digital
• ASCII
• Unicode
• Compression
• Jargon
• AI
• HCI
• other jargon...