The GeForce 8800 GTX GPU implements a massively parallel, unified shader design, consisting of 128 individual stream processors running at 1.35 GHz, and the GeForce 8800 GTS includes 96 stream processors clocked at 1.2GHz. Each stream processor is capable of being dynamically allocated to vertex, pixel, geometry, or physics operations for the utmost efficiency in GPU resource allocation, and maximum flexibility in load balancing shader programs.
In the slide above we see the way current DirectX 9 graphics cards render a scene. The scene in the top picture shows a vertex heavy scene with very little pixel shading needed. Since there is nothing for the pixel shaders to do they are idle. Current generation hardware typically has a much larger pixel shader array than vertex. The second photo shows the oposite scenario, heavy pixel load and little load on vertex. On current generation hardware this would run well but again the vertex shaders are largely idle.
In this slide we see the exact same scenes, but when programmed and accelerated in DirectX 10 there is no idle hardware. Shaders are no longer defined as vertex/pixel/physics, they can be dynamically allocated based on the needs of what is being rendered.
Something that we?ve been hearing a lot of recently with the launch of Core 2 Duo is that we are moving towards a higher performance per watt instead of raw GHz. Architectural efficiency was a leading design criterion for GeForce 8 Series GPUs. Efficient power utilization and management delivers industry leading performance per watt and performance per square millimeter.
Hardware model of fixed function DirectX 9 rendering.
DirectX 10 represents the most significant step forward in 3D graphics APIs since the birth of programmable shaders. Completely built from the ground up, DirectX 10 features powerful geometry shaders, a new ?Shader Model 4? programming model with substantially increased resources and improved performance, a highly optimized runtime, texture arrays, and numerous other features that unlock a whole new world of graphical effects.
Hardware model of dynamic function DirectX 10 rendering.
GeForce 8 Series GPUs include all required hardware functionality defined in Microsoft?s Direct3D 10 (DirectX 10 or DX10) specification and full support for the DirectX 10 unified shader instruction set and Shader Model 4 capabilities. The GeForce 8800 GTX is not only the first shipping DirectX 10 GPU, but it was also the reference GPU for DirectX 10 API development and certification.
New features implemented in GeForce 8800 Series GPUs that work in concert with DirectX 10 features include geometry shader processing, stream output, improved instancing, and support for the DirectX 10 unified instruction set. GeForce 8 Series GPUs and DirectX 10 also provide the ability to reduce CPU overhead, shifting more graphics rendering load to the GPU.