An Energy-Efficient Graphics Processor in 14-nm Tri-Gate CMOS Featuring Integrated Voltage Regulators for Fine-Grain DVFS, Retentive Sleep, and ${V}_{\text{MIN}}$ Optimization

Graphics workloads make highly dynamic use of resources such as execution units (EUs), and thus can benefit from fast, fine-grain dynamic voltage and frequency scaling (DVFS) and retentive sleep. This paper presents a 14-nm graphics processing unit (GPU) prototype with modified EUs which include an integrated voltage regulator (IVR). The IVR enables energy-efficient EU turbo operation, data retention, and $V_{\text {MIN}}$ optimization per EU. Silicon measurements show that IVR-enabled EU turbo operation offers up to 32% (average 29%) energy reduction at constant performance.