Semester 3 / Computer Architecture /Performance

Performance

1 min read Updated Fri Apr 24 2026 03:19:45 GMT+0000 (Coordinated Universal Time)
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Performance Equation

CPU Time=Instruction Count×CPI×Clock Cycle Time\text{CPU Time} = \text{Instruction Count}\times \text{CPI} \times \text{Clock Cycle Time}

Here:

  • CPI - Cycles Per Instruction
    CPI=Total CPU cycles/Instruction count\text{CPI} = \text{Total CPU cycles} / \text{Instruction count}
  • IPC Instructions Per Cycle
    IPC=1/CPI\text{IPC} = 1 / \text{CPI}

Performance can be improved by:

  • Reducing instruction count (better compiler)
  • Lowering CPI (efficient microarchitecture)
  • Reducing clock cycle time (faster hardware)

Performance Measurement and Benchmarking

  • Compare processors using different kinds of benchmarks.
  • Performance is domain-specific.
  • Requirements evolve over time and depend on target devices.