Unit 1 - System architecture, memory and storage

• What is the function of the Arithmetic Logic Unit (ALU) in the CPU?

  It performs calculations and logical decisions.
• What role does the Control Unit play in the CPU?

  It acts as the command centre, directing data movement and coordinating operations within the CPU.
• What is the purpose of the Cache in a CPU?

  It is a small, fast memory located close to or inside the CPU for quick access to frequently used instructions and data.
• What are Registers in the context of a CPU?

  They are super-fast, on-board memory with specific purposes.
• What are the key registers in a CPU and their functions?

  • Accumulator: Temporarily stores results of operations carried out in the ALU.
  • Memory Address Register (MAR): Holds the address of the data or instruction to be fetched or stored.
  • Program Counter (PC): Holds the memory address of the next instruction to be processed.
  • Memory Data Register (MDR): Holds the data or program temporarily when fetched from or sent to memory.
• What is the main factor affecting CPU performance related to clock speed?

  Clock speed is measured in Hertz, indicating the number of cycles per second.
• How does an increase in clock speed affect CPU performance?

  If the clock speed increases, the CPU can perform more cycles per second.
• Why is cache size important for CPU performance?

  Cache memory is an intermediary between main memory and the CPU, making frequently used data available more quickly.
• What is the advantage of having multiple cores in a processor?

  Processors with dual-cores can perform parallel processing with two instructions simultaneously.
• How does the performance of a quad-core processor compare to a single-core processor?

  A quad-core processor can operate faster when executing many tasks simultaneously, but isn't necessarily four times faster if not designed for multiple cores.
• What is the Fetch-Decode-Execute cycle in CPU operations?

  It is the process where the processor fetches an instruction, decodes it, and then executes it one instruction at a time.
• What is the first step when a program is to be run on a computer?

  The program has to be loaded into main memory (RAM).
• Why can't the processor access secondary storage directly?

  The processor can only access data from main memory (RAM).
• What are the key characteristics of RAM?

  • Volatile
  • Stores data/programs/OS that is currently in use
  • Can be written to and read from
• What are the key characteristics of ROM?

  • Non-volatile
  • Stores BIOS/bootstrap loader required to start up the computer
  • Can only be read from and not written to