Building First-Order Energy Modeling Intuition in Computer Architecture Lectures
Christopher Torng · Workshop On Computer Architecture Education · 2023
Computer architecture students today arguably do not have as close a connection to energy as they do to performance. Specifically, they are not trained to reason about energy in a quantifiable way. Architecture students are taught that performance and energy are considered equally important. However, most course material focuses on a performance-driven narrative, meaning that students learn about processors, memories, networks, and systems with a strong sense of the performance implications, but with little intuition for the energy implications. On the other hand, VLSI students concretely learn about energy, but they are immersed in a world of gates and transistors and do not connect their understanding about energy back up to the abstraction of SoC-level components. How can we bridge this gap to enable architecture students to reason about the energy implications of hardware design concepts, directly within a computer architecture class? In this work, we attempt to mitigate these challenges by introducing a teaching methodology that integrates energy into pipeline diagrams. We include examples of specific classroom tools including the representation of an energy map, and we show how pipeline diagrams augmented with an energy map can enable first-order quantitative comparisons of performance, energy, and power across different design points. The approach is simple enough for lecture, in-class activities, and in exams. We hope this approach can train future students in thinking from first principles in evaluating performance-energy tradeoffs.