In the next two decades, diminishing transistor-speed scaling and practical energy limits create new challenges for continued performance scaling. As a result, the frequency of operations will increase slowly, with energy the key limiter of performance, forcing designs to use large-scale parallelism, heterogeneous cores, and accelerators to achieve performance and energy efficiency. Software-hardware partnership to achieve efficient data orchestration is increasingly critical in the drive toward energy-proportional computing.

Our aim here is to reflect and project the macro trends shaping the future of microprocessors and sketch in broad strokes where processor design is going. We enumerate key research challenges and suggest promising research directions. Since dramatic changes are coming, we also seek to inspire the research community to invent new ideas and solutions address how to sustain computing's exponential improvement.