- 90 nanometer low-k dialectic process
- 321 million transistors
- DirectX 9.0c support
- Pixel Shader 3.0
- Vertex Shader 3.0
- 512-bit ring memory bus
- HDR
- Adaptive AntiAliasing
- 500MHz core clock
- 1GHz memory clock
- Crossfire support
ATI decided to be the first video card chip manufacturer to use a 90 nanometer low-k dialectic process for their high-end video cards. To that end, the X1800 cards have 321 million transistors, more than double the previous generation R480 (X850XT PE) and more than NVIDIA's 7800GTX series. All of ATI's X1K cards use the 90 nanometer process. Going forward, it's likely all NVIDIA and ATI cards will use the process as well.
ATI calls the X1K series, "Shader Model 3.0 Done Right". To my mind, NVIDIA was first to market with their GEFORCE 6800 series of video cards, meaning they have the majority of the market share of SM 3.0 video cards. ATI chose to improve their R300 series using Shader Model 2.0 until late this year.
Key features of SM 3.0 include Pixel Shader 3.0 and Vertex Shader 3.0 support. Pixel Shader 3.0 differs from 2.0 in nearly unlimited shader instruction lengths versus 96 on 2.0,dynamic branching and looping of pixel shader programs. Vertex Shader 3.0 differs from VS 2.0 in nearly unlimited shader instruction lengths, 512 static instructions versus 256 in 2.0, and render to texture.
One thing that differentiates ATI's X1K series from NVIDIA's implementation is the ability to do HDR (High Dynamic Range lighting) with Full Scene Anti-Aliasing. Some games are coded to allow both (HL2 Lost Coast), but others like Serious Sam 2, won't work with both enabled. Once the drivers fix the rendering issues with SS2, it's likely make the game look better. ATI also introduced Adaptive AntiAliasing with the X1K. This applies Supersampling to transparent textures and multisampling to everything else.
