NAVIgator Under Fire: Characterizing Voltage Limits and Soft Error Resilience of AMD NAVI GPUs

As semiconductor fabrication scales to smaller technology nodes, process variation presents significant challenges, affecting power consumption, thermal behavior, and voltage stability in silicon compute devices. Conservative voltage guardbands are traditionally used to ensure reliable operation under worst-case process, voltage, and temperature (PVT) variations, but they lead to excessive power consumption. Reducing the supply voltage is a promising technique for improving energy efficiency without sacrificing computational correctness and performance. While extensive research has been conducted on reducing the voltage levels in CPUs and NVIDIA GPUs, the AMD GPU side remains relatively unexplored. Process variation, inherent in semiconductor manufacturing, results in differences in power efficiency, thermal characteristics, and voltage stability even among identical GPUs from the same production batch. In this paper, we present an extensive study on voltage scaling beyond nominal conditions for three modern AMD NAVI GPUs (i.e., RX 7600 XT, 7700 XT, and 7800 XT) executing both conventional benchmarks and PyTorch-based machine learning workloads. We evaluate and present power savings and execution stability by combining undervolting characterization with neutron irradiation physical experiments, contributing to a deeper understanding of undervolting and resilience of AMD GPUs.