While lots of prior studies focused on performance and energy optimizations for caches, their interactions have received much less attention. This is unfortunate since in general the performance-oriented techniques influence energy behavior of the cache, and the energy-oriented techniques usually increase program execution cycles. The overall energy and performance behavior of caches in embedded systems when multiple techniques co-exist remains an open research problem. This paper studies this interaction and illustrates how performance and energy optimizations affect each other. We also point out several potential optimizations that could be based on this study.