You can render a scene on a computer that has more than one processor and make use of some or all of its available processors.
We recommend that you use a single processor when batch rendering a scene that contains a spotlight, material transparency, and raytrace shadows.
To render on a computer with several processors from within Maya
To render on a computer with several processors from a shell or command line (Maya software rendering only)
Render -r sw -n <# of processors to render on> <scene>
(If you do not use the -n option, only one processor is used for rendering.)
Examples (for Maya software rendering only):