The purpose of this paper is to assess the availability of different HVDC transmission system technologies (LCC and VSC) for different transmitted power capacities in order to compare the strengths and weaknesses of each configuration. The matrix-based system reliability (MSR) method has been used since it turns out to be one of the best methods for reliability assessment of multi-terminal HVDC (MTDC) transmission systems taking into account multiple derated states. The results of this study can be useful in the planning and designing stage of HVDC systems.