Exploiting program execution phases to trade power and performance for media workload

Abstract- Processing streaming media comprises several pro-gram phases (often distinct) that are periodic and independent of application data. In this paper we characterize execution of such programs into execution phases based on their dynamic IPC (Instruction Per Cycle) protile. We show that program execu-tion of selected phases can he dynamically boosted by activat-ing additional standby functional units which are otherwise pow-ered down for saving energy. Through simulation we show that speedup ranging from 1.1 to 1.25 can he achieved while reduc-ing the energy-delay product (EDP) for most of the media hench-marks evaluated. Additionally we show that artificially intro-duced stalls during phases of processor underutilization reduces power by around 2 to 4%. 1