AppAdapt: Opportunistic Application Adaptation in Presence of Hardware Variation

In this work, we propose a method to reduce the impact of process variations by adapting the application's algorithm at the software layer. We introduce the concept of hardware signatures as the measured post manufacturing hardware characteristics that can be used to drive software adaptation across different die. Using H.264 encoding as an example, we demonstrate significant yield improvements (as much as 30% points at 0% hardware overdesign), a reduction in overdesign (by as much as 8% points at 80% yield) as well as application quality improvements (about 2.0 dB increase in average peak-signal-to-noise ratio at 70% yield). Further, we investigate implications of limited information exchange (i.e., signature quantization) on yield and quality. We conclude that hardware-signature-based application adaptation is an easy and inexpensive (to implement), better informed (by actual application requirements) and effective way to manage yield-cost-quality tradeoffs in application-implementation design flows.