Lighting is also improved with the GeForce 256 GPU and allows greater interactivity and exceptional light and shadow effects. The potential gaming impact of increased light and shadow realism is very high and from the screenshots I've seen, the future could come sooner than we think. The Specular Lighting is especially eye-catching, but this will remain an untapped feature unless game developers actively support it. Cube Environmental Mapping is a technique of using the innovative features of the GeForce 256 to display reflections and specular lighting in a very realistic way. Essentially, this method uses a six-sided cube to display reflections from a variety of angles. If the game viewpoint shifts, then the cube shifts and displays another "facet" or reflection. In some applications Cube Environment Mapping looks very good, but in others, the reflections have a slightly campy look.

The other major 3D feature of the GeForce 256 is Vertex Skinning. This is actually a quite basic format of smoothing out the rough edges between intersecting polygons, hence the term "vertex". All polygons have straight edges and when trying to depict a detailed scene, such as the act of an elbow bending, the straight edges may crack or show spaces between them. For an example of this phenomenon, check out the graphics on some older games like EA's 4D Boxing. While advanced texture mapping takes care of many of these issues, vertex skinning can improve the underlying polygon vertexes and give a better overall look to the rendered scene and characters.

In addition to the 3D feature set enhancements, NVIDIA has also added a few basic improvements to the GeForce 256 design. The TNT2 chip featured a 128-bit bus and the ability to process two pixels per clock. The GeForce 256 essentially doubles these specs, offering a 256-bit bus (actually 64-bit x 4) and a QuadPixel pipeline capable of processing four pixels per clock. While there are some AGP 4X TNT2 cards, the GeForce 256 ups the ante again with AGP 4X with Fast Writes, an enhanced version of the AGP 2.0 specification that transfers data directly from the CPU to the GeForce 256. Of course, this feature only comes into play if you have a fully-compliant AGP 4X chipset like the i820, but it does help future-proof the card a bit better than competing products.

If there is one caveat with the GeForce 256, it's that older Direct 3D single-texture games may not perform up to expectations. That's because the GeForce 256 is something of an anomaly in 3D chips, in that it has a lower clock speed than its predecessors. Up until the GeForce 256, every new card from 3dfx and NVIDIA has increased the default clock speed. Whether it's the 3dfx path from the 50 MHz Voodoo, to the 90 MHz Voodoo2, 100 MHz Banshee and all the way up to the 183 MHz Voodoo3 3500, or the NVIDIA 90 MHz TNT, to the 125 MHz TNT2 up to the 175 MHz high-end TNT2 Ultras, it's been standard operating procedure to increase clock speeds as new cards are released. The 120 MHz GeForce 256 takes a slightly different route by lowering core speed and adding a QuadPixel engine that can process four pixels per clock cycle, effectively quadrupling performance in multi-texture games. In older D3D single-texture games, only one pixel is processed per clock, causing the TNT2 and TNT2 Ultra to actually outperform the GeForce 256 under certain circumstances. Due to OpenGL games inherently supporting multi-texturing and new D3D games doing the same, this isn't so much a negative as a caveat in case you've got a barrel of old 3D games you've been dying to play.