TEI-Turbo: temperature effect inversion-aware turbo boost for finfet-based multi-core systems

Energy and temperature are the main constraints for modern high-performance multi-core systems. To save power or increase performance, Dynamic Voltage and Frequency Scaling (DVFS) is widely applied in industry. As CMOS technology continues scaling, FinFET has recently become the common choice for multi-core systems. In contrast with planar CMOS, FinFET is observed to have lower delay under higher temperature in super-threshold voltage region, an effect called temperature effect inversion (TEI). Due to this effect, performance can be further improved under power constraints. This work explores TEI-aware performance improvement for power limited multi-core systems. Our experimental results show that on average 15.70% throughput improvement can be achieved in steady state by a TEI-aware DVFS policy over a TEI-agnostic one. In further investigations, we observe multiple sweet spots in the operating voltage/frequency regions resulting from TEI effects. Based on these sweet spot operation regimes, this work introduces a fast algorithm which determines the maximum performance under power constraints. Experimental results confirm its effectiveness by exhibiting a speedup of an average of 45.9X in runtime while keeping resulting performance only 0.22% away from existing state-of-the-art algorithms.