The determination of effective material properties or macroscopic constitutive laws based on the microstructure of heterogeneous media is the major goal in computational micromechanics. Employing fully periodic representative volume elements featuring a periodic topology and mesh in combination with periodic boundary conditions is state of the art. These setups are known to perform the best [2, 1]. However, in the framework of finite element simulations tremendous efforts are required to create models of high quality [3]. This raises the question of the necessity of generating such complex RVEs over other simplifications typically utilized in engineering analysis. In the present work, effects of utilizing simpler RVE model setups to determine effective material parameters and responses are investigated. We focus on influences of different RVE topologies, discretizations and boundary conditions. Here, the case of a fully periodic RVE (periodic topology, mesh and boundary conditions) acts as a reference solution to which the alternative approaches are compared to. Exemplarily so called matrix-inclusion composites, widely used in industrial applications, are considered. General trends for linear and non-linear material behavior will be presented.