@adrmgt Depending on your budget I would recommend 2x [ore more] GTX 1080ti instead of one Titan Xp for GPU rendering in Vray RT. Everything it depends on what render engine are you using, by default Modo, Cinema 4D and Keyshot do not use GPU for render [at this time]. You will need to use extra rendering plugins for that like: Octane Renderer for C4D, Cycles for Cinema 4D, Vray RT for Cinema 4D, RedShift for C4D etc. The release R19 will incorporate AMD ProRenderer by default into C4D. It is a GPU rendering engine that uses OpenCL and runs on GPU. Also Modo is planning to integrate ProRenderer in the next release. You can read more here. For all those software above I would recommend using Windows. Before purchasing make a serious research if you rendering software leverage the GPU power or is only CPU based.