I am running a simulation that takes forever to be completed! It has some switched-cap circuits inside and currently I use moderate simulation and ASP is also enabled, with 16 threads and 24 cores. I wonder if there is any option to break the simulation into smaller parts and use several computers to run parallel simulation.
Actually APS can run across multiple machines - using the "distributed processing" mode. However, this is not that likely to give you more speed up over running on a big multi-core machine - it just allows you to use hardware more efficiently (sometimes people have a large number of smaller core machines, or can schedule jobs easier when asking for only a few cores per machine).
Without knowing the specifics of where the bottlenecks are in your simulation and the statistics about the size of your circuit, number of timesteps and what exactly you are trying to simulate, it's hard to answer such a vague question.
Marc was quite right in trying to suggest alternative strategies for simulating the circuit which could have been much more efficient.
For example, if your simulation is of a relatively small circuit but needs hundreds of millions of timepoints to complete, parallelization won't help you much because time is sequential... you can't do something in parallel if it depends on a previous timestep's results.