There are various renderfarm task / processor configuration strategies, probably the most common being the following three:
- One task for a machine, regardless of processor and core count. The executed software is supposed to do all the threading stuff for itself.
- One task for a processor, so multiprocessor machines run multiple tasks at the same time on all cores of the proc.
- One task for a core, that results in lots of tasks running simultaneously but probably avoiding thread locks.
All of these configurations have some serious pros and cons (mostly related to licensing, network IO, memory usage and threading capability of the softwares) and I'd like to hear your experiences, ideas about them.

This looks like a good general overview of the thought process. It would be great to hear some actual experiences with various configurations though. Profiling such things is not that straightforward (taking all software and task type combinations on the same computer into account) so any first hand experience would be interesting.