Rendering speed is controlled primarily by the speed of the processor. The faster the processor, the faster the rendering is. If you do not have enough RAM, this will force your computer to use virtual memory, which will slow you down with OS X, and slow you down a lot with Windows.
form·Z allows you to position a Distant light source based on Geographic Location and Time of Day / Year. To set this, edit the Distant light by double-clicking on it from the Lights palette
