Heterogeneous microarchitectures trump voltage scaling for low-power cores
Andrew Lukefahr, Shruti Padmanabha, Reetuparna Das, Ronald Dreslinski, Thomas F. Wenisch, Scott A. Mahlke · 2014
Heterogeneous architectures offer many potential avenues for improving energy efficiency in today's low-power cores. Two common approaches are dynamic voltage/frequency scaling (DVFS) and heterogeneous microarchitectures (HMs). Traditionally both approaches have incurred large switching overheads, which limit their applicability to coarse-grain program phases. However, recent research has demonstrated low-overhead mechanisms that enable switching at granularities as low as 1K instructions. The question remains, in this fine-grained switching regime, which form of heterogeneity offers better energy efficiency for a given level of performance?