In this paper, we present a performancemodel for Java applications that allows us to determine the relative performance of the same application on two different platforms. During the execution of Java applications, there is a complex interation between the application, the virtual machine, the operating system and the hardware. As such, an execution performance model should take all of the above into account in the model. A reliable performance model that allows estimating the relative performance has important applications on modern hardware platforms. Modern heterogeneous multi-core processors can use such an estimation to assign a given task to the core that can yield the best performance while consuming as few resources as possible.