Architecture definition is a necessary step in any SoC design project. Traditionally, performance and power have been analyzed using spreadsheets prior to detailed HW simulation. Multicore design complexity, however, has increased and new methods are needed. Static spreadsheet analysis does not take the dynamic behavior of multiple software applications and multiple levels of scheduling and arbitration into account. This bears a great risk of miss-predicting performance, causing under-design, and power, causing over-design, of the system architecture. As described in this paper, multicore optimization for performance and power must happen dynamically and more productively at a higher level of abstraction.