Booster: Reactive core acceleration for mitigating the effects of process variation and application imbalance in low-voltage chi

Lowering supply voltage is one of the most effective techniques for reducing microprocessor power consumption. Unfortunately, at low voltages, chips are very sensitive to process variation, which can lead to large differences in the maximum frequency achieved by individual cores. This paper presents Booster, a simple, low-overhead framework for dynamically rebalancing performance heterogeneity caused by process variation and application imbalance. The Booster CMP includes two power supply rails set at two very low but different voltages. Each core can be dynamically assigned to either of the two rails using a gating circuit. This allows cores to quickly switch between two different frequencies. An on-chip governor controls the timing of the switching and the time spent on each rail. The governor manages a “boost budget” that dictates how many cores can be sped up (depending on the power constraints) at any given time. We present two implementations of Booster: Booster VAR, which v...

• Type: Journal
• Year: 2012
• Where: HPCA
• Authors: Timothy N. Miller, Xiang Pan, Renji Thomas, Naser Sedaghati, Radu Teodorescu
• Keywords: Distributed And Parallel Computing, HPCA 2012, Microprocessor Power, Power Constraints, Power Supply Rails