Energy Efficiency

Learning Outcomes

• Develop a working framework for measuring energy efficiency.

🎥 Lecture Video

Energy efficiency is vital for both mobile devices and warehouse-scale computers in data centers. In a data center, the cost of energy can overshadow the hardware cost after just a year or two.

It is also important to note that power is generally not a good measure of efficiency. Power is merely the rate of exchange, whereas energy is what is actually stored in the battery and what the utility company charges us for.

$$\frac{\text{energy}}{\text{program}} = \frac{\text{instructions}}{\text{program}} * \frac{\text{energy}}{\text{instructions}}$$

$$\text{power} = \frac{\text{energy (J)}}{\text{second}} = \frac{\text{energy (J)}}{\text{instruction}} * \frac{\text{instructions}}{\text{cycle}} * \frac{\text{cycles}}{\text{second}}$$

Watch the video for more information!