Summary form only given. Technology forecasts indicate that device scaling will continue well into the next decade. Unfortunately, it is becoming extremely difficult to harness this increase in the number of transistors into performance due to a number of technological, circuit, architectural, methodological and programming challenges. In this talk, I will argue that the key emerging showstopper is power. Voltage scaling as a means to maintain a constant power envelope with an increase in transistor numbers is hitting diminishing returns. As such, to continue riding the Moore's law we need to look for drastic measures to cut power. This is definitely the case for server chips in future data centers, where abundant server parallelism, redundancy and 3D chip integration are likely to remove programming, reliability and bandwidth hurdles, leaving power as the only true limiter. I will present results backing this argument based on validated models for future server chips and parameters extracted from real commercial workloads. Then I use these results to project future research directions for data center hardware and software.