Both performance and energy cost are important concerns for current data center operators. Traditionally, however, IT and mechanical engineers have separately optimized the cyber vs. physical aspects of data center operations. In contrast, the work presented in this paper jointly considers both the IT - cyber - and the physical systems in data centers, the eventual goal being to develop performance and power management techniques that holistically operate to control the entire complex of data center installations. Toward this end, we propose a balance of payments model for holistic power and performance management. As an example of coordinated data center management system, the energy-aware cyber-physical system (EaCPS) uses an application controller on the cyber side to guarantee application performance, and on the physical side, it utilizes electric current-aware capacity management (CACM) to smartly place executables to reduce the energy consumption of each chassis present in a data center rack. A web application, representative of a multi-tier web site, is used to evaluate the performance of the controller on the cyber side, the CACM control on the physical side, and of the holistic EaCPS methods in a mid-size, instrumented data center. Results indicate that coordinated EaCPS outperforms the cyber and physical control modules working separately.