It was looking like dividing by parts, a scene for rendering and reading this,
http://wiki.blender.org/index.php/Doc:2.4/Manual/Render/Options
see Xparts
and Yparts
but on blender 2.4, but the interface has changed I currently have the 2.63 and download the, 2.73 and see but I can not see the menu for Xparts and Yparts, someone can say me if these options are even, and if I could show where.
Thanks.