910GL datasheet(236/426 Pages) INTEL

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Functional Description

236

Datasheet

and two digital (SDVO ports B and C). The ports will be explained in more detail later in the

chapter.

The entire IGD is fed with data from its memory controller. The GMCH’s graphics performance

is directly related to the amount of bandwidth available. If the engines are not receiving data fast

enough from the memory controller (e.g., single-channel DDR333), the rest of the IGD will also

be affected.

The rest of this chapter will focus on explaining the IGD components, their limitations and

dependencies.

12.6.1

3D Engine

The 3D engine of GMCH has been designed with a deep pipelined architecture, where

performance is maximized by allowing each stage of the pipeline to simultaneously operate on

different primitives or portions of the same primitive. GMCH supports Perspective-Correct

Texture Mapping, Multitextures, Bump-Mapping, Cubic Environment Maps, Bilinear, Trilinear

and Anisotropic MIP mapped filtering, Gouraud shading, Alpha-blending, Vertex and Per Pixel

Fog and Z/W Buffering.

The 3D pipeline subsystem performs the 3D rendering acceleration. The main blocks of the

pipline are the Setup Engine, Scan Converter, Texture Pipeline, and Raster Pipeline. A typical

programming sequence would be to send instructions to set the state of the pipeline followed by

rending instructions containing 3D primitive vertex data.

The engine’s performance is dependent on the memory bandwidth available. Systems that have

more bandwidth available will outperform systems with less bandwidth. The engine’s

performance is also dependent on the core clock frequency. The higher the frequency, the more

data is processed.

12.6.2

Setup Engine

The setup stage of the pipeline takes the input data associated with each vertex of a 3D primitive

and computes the various parameters required for scan conversion. In formatting this data, the

GMCH maintains sub-pixel accuracy.

12.6.2.1

3D Primitives and Data Formats Support

The 3D primitives rendered by GMCH are points, lines, discrete triangles, line strips, triangle

strips, triangle fans and polygons. In addition to this, GMCH supports the Microsoft DirectX*

Flexible Vertex Format (FVF), which enables the application to specify a variable length of

parameter list obviating the need for sending unused information to the hardware. Strips, Fans and

Indexed Vertices as well as FVF, improve the vertex rate delivered to the setup engine

significantly.

910GL датащи(PDF) 236 Page - Intel Corporation