Wireless NoC and Dynamic VFI Codesign: Energy Efficiency Without Performance Penalty

Abstract

Multiple voltage frequency island (VFI)-based designs can reduce the energy dissipation in multicore platforms by taking advantage of the varying nature of the application workloads. Indeed, the voltage/frequency (V/F) levels of the VFIs can be dynamically tailored by considering the workload-driven variations in the application. Traditionally, mesh-based networks-on-chip (NoCs) have been used in VFI-based systems; however, they have large latency and energy overheads due to the inherently long multihop paths. Consequently, in this paper, we explore the emerging paradigm of wireless NoC (WiNoC) and demonstrate that by incorporating WiNoC, VFI, and dynamic V/F tuning in a synergistic manner, we can design energy-efficient multicore platforms without introducing noticeable performance penalty. Our experimental results show that for the benchmarks considered, the proposed approach can achieve between 5.7% and 46.6% energy-delay product (EDP) savings over the state-of-the-art system and 26.8% and 60.5% EDP savings over a standard baseline non-VFI mesh-based system. This opens up a new of class of codesign approaches that can make WiNoCs the communication technology of choice for future multicore platforms.