The talk will begin with a historical discussion of innovations in processor architecture. In every case, the innovations that define current processors were actually developed decades ago. An important issue, then, is whether there are any new techniques waiting to be discovered. In order to continue making significant performance gains, a number of obstacles must be simultaneously overcome. These obstacles are described using an analytical performance model. The potential of a number of actively researched techniques will then be considered; these include deep pipelines, speculative multi-threading, and next-generation branch prediction. Finally, in light of the history, obstacles, and available techniques, the potential and direction of future innovations will be discussed.