Monte Carlo radiation transport codes are in wide use in research and industry throughout the world. Although the codes have been well tested in some specific applications the tests have generally been against integral data, e.g. dose, total energy deposit or activation. In this paper we present the first results for a photon transport benchmark experiment testing the capability to predict absolute differential results, specifically pulse height counting rate spectra in a high purity germanium detector. There is no scaling employed to help the predictions match the experimental data.