The design complexity of modern high performance processors calls for innovative design methodologies for achieving time-to-market goals. New design techniques are also needed to curtail power increases that inherently arise from ever increasing performance targets. This paper describes new design approaches employed by the POWER8 processor design team to address complexity and power consumption challenges. Improvements in productivity are attained by leveraging a new and more synthesis-centric design methodology. New optimization strategies for synthesized macros allow power reduction without sacrificing performance. These methodology innovations contributed to the industry leading performance of the POWER8 processor. Overall, POWER8 delivers a 2.5x increase in per-socket performance over its predecessor, POWER7+, while maintaining the same power dissipation.