University of Miami School of Business Administration
Several recent papers have been published proposing the use of dual-voltage rails and fast switching circuitry to address bottlenecks or overcome process variation in near-threshold computing systems. The published results yield boosting transition times of 7-10ns, which, in some cases, is needed for the architectural contributions to be justified. However, the analysis of these circuits assumed incorrect core models, ideal off-chip power supplies, and non-worst case scenarios. When realistic bonding capacitance and inductance are included, proper core models are used, and worst-case simulation is performed these transitions times can be off by 3x, adversely impacting the potential gains in the system.