AC82G41SLGQ3 Datasheet, PDF (533/604 Pages) Intel Corporation – Intel® 4 Series Chipset Family

Functional Description
13.4.1.1
3D Engine Execution Units (EUs)
The 3D processing hardware includes support for 2 more EUs over the previous
generation. The EUs perform 128-bit wide execution per clock and are support SIMD8
instructions for vertex processing and SIMD16 instructions for pixel processing.
13.4.1.2 3D Pipeline
13.4.1.2.1
Vertex Fetch (VF) Stage
The VF stage performs one major function: executing 3DPRIMITIVE commands. Some
enhancements have been included to better support legacy DirectX 3D APIs as well as
OpenGL.
13.4.1.2.2
Vertex Shader (VS) Stage
The VS stage of the 3D pipeline is used to perform shading of vertices output by the VF
function. The VS unit will, thus, produce an output vertex reference for every input
vertex reference received from the VF unit, in the order received.
13.4.1.2.3
Geometry Shader (GS) Stage
The GS stage receives inputs from the previous VS stage. Compiled application-
provided GS shader programs specify an algorithm to convert the vertices of an input
object into some output primitives. For example, a GS shader may convert lines of a
line strip into polygons representing a corresponding segment of a blade of grass
centered on the line. Or it could use adjacency information to detect silhouette edges of
triangles and output polygons extruding out from the those edges.
13.4.1.2.4
Clip Stage
The CLIP stage can be used to perform general processing on incoming 3D objects.
However, it also includes specialized logic to perform a ClipTest function on incoming
object. The Clip Test optimizes generalized 3D Clipping. The Clip unit examines the
position of incoming vertices, and accepts/rejects 3D objects based on its Clip
algorithm.
13.4.1.2.5
Strips and Fans Stage
The Strips and Fans (SF) stage of the 3D pipeline is responsible for performing setup
operations required to rasterize 3D objects. The outputs from the SF stage to the
Windower stage comprise of implementation-specific information required for the
rasterization of objects and also supports clipping of primitives to some extent.
13.4.1.2.6
Windower/IZ (WIZ) Stage
The WIZ unit performs an early depth test, a major performance-optimization feature
where failing pixels are removed; thus, eliminating unnecessary processing overhead.
The Windower uses the parameters provided by the SF unit in the object-specific
rasterization algorithms. The WIZ unit rasterizes objects into the corresponding set of
pixels.
The Windower is also capable of performing dithering, whereby the illusion of a higher
resolution when using low-bpp channels in color buffers is possible. Color dithering
tends to diffuse the sharp color bands seen on smooth-shaded objects.
Datasheet
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