Deployment of better than worst-case design: solutions and needs

The advent of nanometer feature sizes in silicon fabrication has triggered a number of new design challenges for computer designers. These challenges include design complexity and operation in the presence of environmental and device uncertainty. To make things worse, these new challenges add to the many challenges that designers already face in order to scale system performance while meeting power and reliability budgets. Current design objectives are being met by applying even more engineers and increasing overall design times, an unsustainable trend. This paper overviews a novel design strategy, called better than worst-case design, that addresses these challenges through a methodology based on separating the concerns of performance and reliability by coupling complex design components with simple reliable checker mechanisms. We present the key aspects of better than worst-case design and cover some recently proposed solutions that deploy this technique in application domains ranging from microprocessors to digital signal processors. We then highlight a few aspects that need to be addressed to make this approach more practical in general contexts and suggest possible solutions.