Lab 2: Energy Efficiency in Programming Languages
This lab explores the energy efficiency implications of programming language choices.
Key Findings on C Energy Efficiency
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C tends to be more energy efficient than managed languages for several reasons:
- Minimal runtime overhead (no garbage collection, JIT compilation)
- Direct memory access without indirection
- More efficient CPU instruction usage
- Lower memory footprint
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Research supports C efficiency: Studies like “Energy Efficiency across Programming Languages” (Pereira et al.) typically show C among the most energy-efficient languages, with Python and Java often using 2-3x more energy for equivalent tasks.
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Trade-offs exist: C’s efficiency comes at the cost of development time, safety, and maintainability.
Broader Energy Considerations
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Device usage profile matters:
- For always-on server applications, language efficiency can significantly impact energy usage
- For mobile/IoT devices with mostly idle time, language choice matters less than sleep/wake efficiency
- For rarely-run applications, implementation efficiency matters less than algorithmic efficiency
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Embodied carbon perspective:
- Manufacturing a device typically represents 50-80% of its lifetime carbon footprint
- Extending device lifespan through more efficient software can reduce overall environmental impact
- For most consumer devices, the energy used during manufacturing exceeds the energy used during operation
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Relative impact of programming language:
- For compute-intensive applications (ML, rendering, simulation), language choice is significant
- For I/O-bound or user-interaction applications, language efficiency has minimal impact
- System architecture decisions usually have greater energy impact than language choice