An Analytical Model for Performance-Carbon Co-Optimization of Edge AI Accelerators

ASIC accelerators have emerged as vital solutions to deploy various AI workloads, especially in resource-constrained edge scenarios. Existing analytical models for guiding the architectural exploration of these accelerators focus solely on performance and energy efficiency metrics while overlooking the carbon cost. In contrast, existing carbon cost models focus on analyzing specific hardware configurations but lack the support for exploration of the optimal architecture choices and the trade-off analysis between performance and carbon cost. To fill this gap, this paper aims to analyze the impact of different architecture configurations from both the performance and carbon perspectives, exploring the trade-off between the performance and carbon cost for AI accelerator design. For this purpose, we first built an analytical model, named <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CarbonSpot</i>, capable of modeling and estimating both performance and carbon cost for any accelerator architecture in the design space. Then, by benchmarking the overhead of these AI accelerators under MLPerf-Tiny and MLPerf-Mobile workloads, we show that architectures solely optimized for performance and energy efficiency produce 58× more carbon emissions than designs designed for the highest carbon efficiency. Importantly, co-optimized architectural choices exist, with only <20% drop in performance and <6% overhead in carbon costs when compared to the respective best cases optimized for either maximum performance or minimal carbon impact. The model is open-sourced at: https://github.com/KULeuven-MICAS/carbonspot.