Integrated Graphics Subsystem
6.2 Functional Description
The Intel 915G/GV GMCH component includes an integrated graphics controller (IGC). (Figure
6-1). The IGC can directly drive an external, analog multi-scan monitor at resolutions up to and
including 2048 x 1536 pixels. The IGC includes a memory management feature that allocates
portions of system memory for use as the frame buffer and for storing textures and 3D effects.
The IGC provides two SDVO channels that are multiplexed through the PCI Express graphics
interface. These SDVO ports may be used by an Advanced Digital Display (ADD2) card
installed in the PCI Express graphics slot in driving two digital displays with a 200-megapixel
clock. (NOTE: SDVO/ADD2 cards need to match the layout (normal or reversed) supported by
the system board slot.)
The SSF, ST, MT, and CMT sytems may be upgraded by installing a separate PCI-E graphics
card in the PCI Express x16 slot, which disables the onboard IGC. All systems may be also be
upgraded by installing a PCI graphics card in the PCI 2.3 slot.
PCI Express x16
Graphics slot [1]
NOTES:
[1] SFF, ST, MT, and CMT only
[2] 82915G GMCH only
Figure 6-1. 915G-Based Graphics, Block diagram
The Integrated Graphics Controller provides the following functions:
Rapid pixel and texel rendering using special pipelines that allow 2D and 3D operations to
overlap, speeding up visual effects, reducing the amount of memory for texture storage.
Zone rendering for optimizing 3D drawing, eliminating the need for local graphics memory
by reducing the bandwidth.
Dynamic video memory allocation, where the amount of memory required by the application
is acquired (or released) by the controller.
Intelligent memory management allowing tiled memory addressing, deep display buffering,
and dynamic data management.
Provides two serial digital video out (SDVO) channels for use by an appropriate ADD2
accessory card.
6-2
RGB
Monitor
PCI-E
& SDVO Data
82915G/GV GMCH
Integrated
SDRAM
Graphics
Controller
Controller
PCI Expr. I/F [2]
361834-001
DDR
SDRAM
(System
Memory)
Technical Reference Guide