POV-Ray
The Persistence of Vision Ray-Tracer was developed from DKBTrace 2.12 (written by David K. Buck and Aaron A. Collins) by a bunch of people (called the POV-Team) in their spare time. It is a high-quality, totally free tool for creating stunning three-dimensional graphics. It is available in official versions for Windows, Mac OS/Mac OS X and i86 Linux. The POV-Ray package includes detailed instructions on using the ray-tracer and creating scenes. Many stunning scenes are included with POV-Ray so you can start creating images immediately when you get the package. These scenes can be modified so you do not have to start from scratch. In addition to the pre-defined scenes, a large library of pre-defined shapes and materials is provided. You can include these shapes and materials in your own scenes by just including the library file name at the top of your scene file, and by using the shape or material name in your scene. Since this is free software feel free to download this version and try it out on your own.
The most significant change from the end-user point of view between versions 3.6 and 3.7 is the addition of SMP (symmetric multiprocessing) support, which, in a nutshell, allows the renderer to run on as many CPU's as you have installed on your computer. This will be particularly useful for those users who intend on purchasing a dual-core CPU or who already have a two (or more) processor machine. On a two-CPU system the rendering speed in some scenes almost doubles. For our benchmarking we used version 3.7 beta 35a, which is the most recent version available. The benchmark used all available cores to complete the render.
Benchmark Results: Though the slowest of all the chips tested, the AMD Phenom II 910e fared much better while testing single cores. It was 34% slower than the I7 920 was while using all cores but only 3.5% slower while testing 1 core and only 15% slower than the AMD Phenom II 940 which is comparable to using all the cores.