We present timings and performance numers for a new short range three dimensioan (3D) molecular dynamics (MD) code, SPa.SM, on the connection Machine-5 (CM-5) . We demostrate that runs with more than 108 particles are now possible on masively parallel MIMD computers. TO the best of our knowledge this is at least an order of magnitude more particles that waht has previously been reported. Typical production runs show susteined perfomance (including communication) in the range of 47-50 GF lops on a 1024 node CM-5 with vector units (VUs). The speed of the code scales linearly with the number of processors with the number of particles and shows 95% parallel efficeincy in the speedup