HP Deskpro EX Technical Reference Manual page 131

HSync
HSync
Monitor
Connector
RGB
Figure 6-2. 82815 GMCH Integrated Graphics Subsystem
The integrated graphics controller includes special enhancements for 2D operations. Motion
compensation logic is included to improve performance during software decoding of MPEG2
video. Hardware cursor and overlay engines relieve software processing and provide independent
gamma correction, saturation, and brightness control. The 230-MHz RAMDAC can support a
variable-scan rate monitor up to a maximum resolution of 1600 x 1200 with 256 colors. Video
BIOS for the controller is held in the system BIOS ROM and copied into systems memory at
runtime for maximum performance.
An optional 4-MB Graphics Performance Accelerator (GPA) card may be installed in the AGP slot
to be used by the integrated controller as a display cache. The GPA card allows the graphics
controller to simultaneously render graphics to the Z-buffer (in the display cache) while processing
textures in a portion of system memory, increasing 3D performance substantially. The integrated
i740 graphics controller uses, through the AGP I/F, a specific amount of system memory. This
memory is allocated as follows:
Video BIOS – 512 or 1024 kilobytes. An OS report of available system memory will be the total
amount installed LESS this amount.
Graphics Memory – Prior to the PV 4.x driver being loaded, the graphics memory will be one
megabyte for supporting standard VGA modes. After driver load, memory allocation will be set by
the Dynamic Video Memory Technology (DVMT) for rendering, Z-buffering, and displaying
according to need and total system memory availability. The following table indicates the amount
of memory allocated depending on operating system and memory availability.
OS Type and
Sys. Mem. Amount
Windows 98 w/32 MB
Windows 98 w/64 MB
Windows 98 w/128 MB
Windows NT 4.0 w/64 MB
Windows NT 4.0 w/128 MB
Windows 2000 w/64 MB
Windows 2000 w/128 MB
82815 GMCH
i740-Equiv. Graphics Controller
2D
Engine
RAM
Pipelined
DAC
Preprocessor
Total Graphics Memory
w/o GPA Card
10 MB
10 MB
10 MB
Compaq Deskpro EX Series of Personal Computers
First Edition - August 2000
Technical Reference Guide
3D
Engine
AGP
4X I/F
AGP Bus
Total Graphics Memory
w/4 MB GPA Card
6 MB
9 MB
9 MB
9 MB
FSB I/F &
SDRAM
Cntlr.
9 MB
12 MB
12 MB
12 MB
12 MB
12 MB
12 MB
6-3