Cycles per Instruction Calculator
Calculate CPU performance metrics including CPI, MIPS, and execution time for different instruction mixes.
Instruction Configuration
System Parameters
Instruction Types
Total frequency should equal 100%. Current total: 100%
Performance Visualization
Performance Metrics
Average CPI:
MIPS:
Execution Time:
Total Cycles:
Instruction Breakdown
| Instruction Type | Frequency | CPI | Instructions | Cycles | % of Total Cycles |
|---|
Performance Analysis
Performance Rating:
Bottleneck Analysis:
Optimization Suggestions:
About Cycles per Instruction (CPI)
What is CPI?
Cycles per Instruction (CPI) is a key performance metric in computer architecture that measures the average number of clock cycles required to execute one instruction. It's calculated as the total number of clock cycles divided by the total number of instructions executed. Lower CPI values generally indicate better processor performance.
Key Formulas
- Average CPI: Σ(CPI_i × Frequency_i) where i represents each instruction type
- Total Cycles: Total Instructions × Average CPI
- Execution Time: Total Cycles ÷ Clock Frequency
- MIPS: (Clock Frequency ÷ Average CPI) ÷ 1,000,000
- Performance: 1 ÷ Execution Time
Instruction Types & Typical CPI Values
Simple Instructions
- • ALU Operations: 1-2 cycles
- • Register-Register: 1 cycle
- • Simple Branches: 1-2 cycles
- • Logical Operations: 1 cycle
Complex Instructions
- • Memory Load/Store: 2-5 cycles
- • Floating Point: 3-10 cycles
- • Division: 10-50 cycles
- • Cache Misses: 10-100+ cycles
Performance Optimization
- Reduce High-CPI Instructions: Minimize floating-point and memory operations when possible
- Improve Cache Performance: Better cache design reduces memory access cycles
- Pipeline Optimization: Reduce pipeline stalls and hazards
- Instruction Scheduling: Reorder instructions to minimize dependencies
- Branch Prediction: Improve branch prediction to reduce misprediction penalties
How to Use This Calculator
- Set the system parameters (clock frequency and total instructions)
- Define instruction types with their frequencies and CPI values
- Ensure the total frequency equals 100%
- Click "Calculate CPI & Performance" to analyze the results
- Review the performance metrics and optimization suggestions
- Use the visualization to understand the instruction mix impact
Applications
- Processor Design: Evaluate and compare different CPU architectures
- Compiler Optimization: Analyze the impact of different compilation strategies
- Performance Tuning: Identify bottlenecks in program execution
- Benchmark Analysis: Compare performance across different workloads
- Academic Research: Study computer architecture performance characteristics