Heavy ion collisions allow the study of quantum chromodynamics in the dense, high energy regime. The color glass condensate (CGC) model is a classical, effective field theory that describes the colliding nuclei as flat, Lorentz contracted discs. The present C++ code can simulate the early stages of heavy ion collisions in the CGC framework with nuclei of finite thickness. All equations of motion and constraints as well as the Hamilton density are derived from the CGC action. Additionally, an alternative discretization of the Poynting vector, which allows better conservation of Poyntings theorem, is obtained. Compared to its predecessor, the OpenPixi simulator, the new C++ code should have more predictable scaling, run faster and use less memory. In order to confirm this, a set of tests and performance benchmarks were conducted. Furthermore, the emergence of well-known features like the pressure anisotropy and Gaussian rapidity profiles were studied in comparison with OpenPixi.