HP 8200 tower manual IGC Memory Allocation with Windows XP, System Memory Installed Pre-allocated

Integrated Graphics Subsystem

The total memory allocation is determined by the amount of system memory installed in a system, along with the BIOS settings, operating system, and system load. Table 6-2 shows the pre-allocation memory amounts.

Table 6-2.

IGC Memory Allocation with Windows XP

System Memory Installed	Pre-allocated	DVMT
0.5 GB	32 MB	128 MB
1.0 GB	32 MB	512 MB
1.5 GB	32 MB	768 MB
> 2GB	32 MB	1024 MB

System memory that has been pre-allocated is not seen by the operating system, which will report the total amount of memory installed less the amount of pre-allocated memory.

Systems running Windows Vista or Windows 7 use Protected Audio Video Path (PAVP) to ensure smooth playback of high-definition video by off-loading video decoding from the processor to the IGC. Table 6-3 shows the PAVP memory usage for Windows Vista and Windows 7.

Table 6-3.

IGC Memory Allocation with Windows Vista or Windows 7

	Available	Total	Shared
System Memory	System	Available	System
Installed	Memory	Graphics Memory [1]	Memory [2]
1 GB	952 MB	252 MB	124 MB
2 GB	1976 MB	764 MB	636 MB
4 GB	4024 MB	1759 MB	1631 MB
6 GB	6072 MB	1759 MB	1631 MB
8 GB	8120 MB	1759 MB	1631 MB

NOTES:

[1]Total amount of memory available for graphics as reported by the OS.

[2]Shared System Memory (memory dynamically allocated for graphics use).

Both the “Total Available... and “Shared System...” memory amounts will vary depending on each system’s memory configuration.

The integrated graphics controller will use, in standard VGA/SVGA modes, pre-allocated memory as a true dedicated frame buffer. If the system boots with the OS loading the Extreme Graphics drivers, the pre-allocated memory will then be re-claimed by the drivers and may or may not be used in the “extended” graphic modes. However, it is important to note that pre-allocated memory is available only to the integrated graphics controller, not to the OS.

The DVMT function is an enhancement over the Unified Memory Architecture (UMA) of earlier systems. The DVMT of the Q67 Express selects, during the boot process, the maximum graphics memory allocation possible according on the amount of system memory installed:

The actual amount of system memory used in the “extended” or “extreme” modes will increase and decrease dynamically according to the needs of the application. The amount of memory used solely for graphics (video) may be reported in a message on the screen, depending on the operating system and/or applications running on the machine.

For viewing the maximum amount of frame buffer memory available go to the MS Windows Control Panel and select the Display icon, then > Settings > Advanced > Adapter.

Technical Reference Guide www.hp.com 6-3