Also be aware that some plugins use all the cores outside of rendering such as X-Particles and TFD uses the GPU (Nvidia CUDA cores) for generating the simulation. There are also other programs such as video editing and compositing programs that are fully multi-threaded.
I bring this up because if you are considering Xeon's then you are considering workstations rather than PC's and if you are going into those price ranges then you should consider the performance benefits a workstation is going to give all your software rather than just C4D. Otherwise you may be happier with spending less for a PC.
Dave
I feel like it could benefit from a handful of zombies sprawled all over it, with a priest equipped with a high powered rifle by the clock tower there, with a caption "keep off the lawns"