Dynamic Power and Energy Management for NCFET-Based Processors

Power and energy consumption are the key optimization goals in all modern processors. Negative capacitance field-effect transistors (NCFETs) are a leading emerging technology that promises outstanding performance in addition to better energy efficiency. The thickness of the added ferroelectric layer as well as frequency and voltage are the key parameters that impact the power and energy of NCFET-based processors in addition to the characteristics of runtime workloads. Unlike existing CMOS technologies, operating NCFET-based processors at a higher frequency than the required minimum can result in power/energy minimization. The optimal operating point, however, strongly depends on dynamic workload characteristics and technology parameters. In this work, we propose and implement the first NCFET-aware power and energy management approach that minimizes the processor's power and energy through optimal voltage/frequency selection under different runtime scenarios. Such an NCFET-aware approach does not result in any tradeoff between power/energy and performance. Instead, it can achieve higher performance while minimizing energy. A comprehensive, simulation-based evaluation of our runtime management under realistic workloads demonstrates up to 58% energy saving with 2.1\times higher performance, and 46% power saving compared to conventional NCFET-unaware management techniques, over the total execution of a benchmark. Compared to state-of-the-art NCFET-aware management techniques, our technique provides up to 49% energy saving and 32% power saving.