First question is whether multithreaded execution will help. Do you have cells with lots of compartments and mechanisms? i.e. requiring at least a couple thousand ODEs per cell? If no, multithreaded won't help. If yes, the next thing is to make sure that it's compatible with multithreaded execution--see
http://www.neuron.yale.edu/neuron/static/ ... ml#Threads, and also see
http://www.neuron.yale.edu/phpBB/viewto ... =22&t=1476especially with regard to using mkthreadsafe to check and fix mod files.
For any given model, discovering if multithreaded execution is beneficial, and how many threads to use, is an empirical question. It's probably a good idea to use the GUI--specifically the RunControl panel and the NEURON Main Menu / Tools / Parallel Computing tool--to run a few interactive tests in order to decide on appropriate simulation parameters.