I found this by searching the help file for process-based...
If you go to Tools~Manage Players. Select a PC and expand the Machine Settings. This will show the calculated max. threads and processes and there is an option to override the defaults. I think this info. also is shown in the script assignment tab.
Searching the help for "maximum number of processes" (no quotes) got me to, "The Conductor calculates how many virtual users will be active per 64 MB of RAM, based on the values you provide in these fields. For more information, see Machines Dialog Box."
A problem is a difference between what is perceived and what is desired, that
we want to reduce (Dewey 1933)