CISC vs RISC describe the RISC architecture describe the CISC architecture compare RISC and CISC 


The two main types of computer processors are: 

  • Complex Instruction Set Computing (CISC) 
  • Reduced Instruction Set Computing (RISC) 


  • Complex Instruction Set
  • Non-fixed size of instruction, e.g. instructions have variable format.
  • Memory-to-memory
  • Uses complex instructions each of which may take multiple cycles.
  • Single register set, less registers than in RISC
  • Many instructions and addressing modes are available.
  • Has a complicated and expensive processor design.
  • Has more components on CPU than a RISC processor
  • Generates more heat
  • Requires heat sink/fan
  • Use less RAM
  • Require more power


  • Reduced Instruction Set.
  • Fixed size of instruction
  • Register-to-register
  • A limited number of instructions is available.
  • An instruction performs a simple task
  • Complex tasks can only be performed by combining a number of simple tasks so a task may take a number of machine cycles.
  • Can perform simple tasks very quickly.
  • Simple processor design.
  • Programs can run faster due to simpler instructions executing at a faster rate. 
  • Less components on CPU
  • Produces less heat
  • Use more RAM than CISC
  • Used in tablets and mobile devices



  1. Name features for CISC and RISC.
  2. Explain differences between CISC and RISC.
  3. What type of processor is used for laptop? Why?


Ex. 1

Exam questions:

Категория: System architecture | Добавил: bzfar77 (21.01.2021)
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