Assessing Processor Sustainability Using the First-Order FOCAL Carbon Model

To overcome the inherent data uncertainty regarding the sustainability of computing devices in general and processors in particular, this paper proposes FOCAL, a parameterized first-order carbon model to assess processor sustainability from first principles. FOCAL’s normalized carbon footprint (NCF) metric guides computer architects to holistically optimize chip area, energy and power consumption to reduce a processor’s environmental footprint. We use FOCAL to analyze and categorize a broad set of archetypal processor mechanisms into strongly, weakly or less sustainable design choices, providing insight and intuition into how to reduce a processor’s environmental footprint with implications to both hardware and software. A case study illustrates a pathway for designing strongly sustainable multicore processors delivering high performance while at the same time reducing their environmental footprint.