In the Forums...
Posted: November 18th, 2002
Let's start by taking a look at the heart of the graphics card, the GPU.
NVIDIA GeForce FX GPU features:
8-Layer metal transistors (0.13 Micron) Left, and the edge of a wafer, (Right).
Nvidia also moved to the 0.13 micron fabrication process using copper. This allows for 25% smaller, faster transistors, 36% lower power consumption, and 500MHz operation. You should also expect to see implementations of the new card running with the new DDR2 memory at 1.8ns, and data rates higher than 1.0GHz. This again doubles the peak bandwidth from 600MHz to 1GHz to local memory. The picture on the left is look at the actual die, while the picture on the left is a transistor, notice the 8 layers.
Being able to generate 8 pixels per clock cycle allows the GPU to render extremely complex scenes in real time without having to be limited to a smaller section of your screen, and it also allows for extremely fast fill-rate. In comparison, the Ti4600 had a 4-pixel per clock cycle fill rate, so this effectively doubles pixel throughput from previous generations. This seems to be a trend with the GeForce FX. You'll see what I mean shortly.
The new Intellisample technology incorporates several key technologies such as the ability to quickly clear the color buffer in hardware, which improves overall graphics performance. In open GL (OGL), clearing the color buffer is basically clearing the screen, speeding this process up, in turn speeds up screen draws.
The GeForce FX GPU's now support a new 6XS FSAA mode under Direct3D, and a new 8X under both Direct3D and OGL. You can set the new modes within the control panel, and through the latest DirectX version. The 6XS mode calculates 1.5 times the as 4XFSAA, and the 8X mode doubles to 4 times the samples for the highest level of image quality. If this GPU follows the same path that the older Ti4600 did, seeing games running on 8X FSAA will be not only stunning, but totally smooth on higher end systems, say 1GHz and up. One interesting thing to note about the new Intellisample technology is that it encompasses more than just the anti aliasing itself. It also incorporates a proprietary form of loss-less data compression with a 4:1 compression ratio for color, which is done in hardware. This means that compression and decompression are done in real time. Because the compression is completely loss-less, you get way better memory efficiency, anti aliasing is sped up to the point that all modes of AA are achievable with little to no loss of frame rate or performance, and image quality is not reduced at all.
This video can be seen at www.yeahthemovie.de I suggest taking a look at what the GeForce FX is truly capable of, but be warned, you might want to hang on to your jaw, as I now have a nasty bruise from where mine hit the floor.
Intellisample also incorporates 2 more important technologies into the total package, they are Dynamic gamma correction, a process in which the new shaders deal with gamma correction. This process give you significantly better color. Last, Intellisample raises the bar for image quality by monitoring the geometry and texture content continuously to make intelligent trade-offs that enhance performance, without producing artifacts. Turning this feature on will give you very good visuals, though there is also a more conservative setting which uses more traditional algorithms for anisotropic and trilinear filtering. This should be an exciting feature to see in person. It sounds like Nvidia is doing all it can to bring not only unparalleled speed to the desktop, but also untouchable graphical detail and quality. Basically, you are seeing the game as it is intended by the guy spending 4 years of his life writing code.
The images above are examples from two of the forthcoming Nvidia demos. The demo on the left shows a classic truck begin to rust and fall apart in real time, while the images on the right are stills from another demo, called "Dawn". The amazing thing about the picture on the right is that the skin shader uses a complex combination of color maps, specular maps, and blood charactaristic maps, which produce very lifelike skin. The level of precision it takes to do this can only be found in the new GeForce FX. We'll talk more about the necessity of higher precision later.