Advantech PCA-6186 user manual Introduction, Dynamic Video Memory Technology

Chapter 5 AGP VGA Setup

5.1 Introduction

As quoted from "Intel® 845G chipset Graphics Chipset Controller Hub (GMCH) Rev. 1.0 May 2002.”:

The Intel® 845G Graphics Memory Controller Hub (the 845G GMCH) is Intel’s first memory controller hub with integrated graphics for the Intel Pentium® 4 processor. The 845G GMCH, with its new architecture graphics engine, delivers not only high 2D/3D graphics performance, but also provides efficient, high bandwidth communication channels connect- ing the processor, the memory, the I/O subsystem, and other components together to deliver a stable mainstream desktop platform solution. The features include:

•Built-in 2D/3D AGP VGA controller.

•Integrated 350MHz RAMDAC that can directly drive a progressive scan analog monitor up to a resolution of 2048x1536 at 60MHz

•Up to 1600 x 1200 x 32 resolution at 85 Hz refresh.

•H/W motion compensation assistance for s/w MPEG 2 decoding.

•Software DVD at 30 fps Full Screen.

5.2Dynamic Video Memory Technology

The following is quoted from "Intel® 845G/845GL Chipset Dynamic Video Memory Technology" Rev. 1.2 June 2002”:

Dynamic Video Memory Technology (DVMT) is an enhancement of the UMA concept, wherein the optimum amount of memory is allocated for balanced graphics and system performance, through Direct AGP known as Non-Local Video Memory (NLVM), and a highly efficient memory utilization scheme. DVMT ensures the most efficient use of available memory ñ regardless of frame buffer or main memory sizing ñ for maxi- mum 2D/3D Graphics performance. DVMT dynamically responds to system requirements, and applications demands, by allocating the proper amount of display, texturing and buffer memory after the operating sys- tem has booted. For example, a 3D application when launched may require more vertex buffer memory to enhance the complexity of objects, or more texture memory to enhance the richness of the 3D environment. The operating system views the integrated graphics driver as an applica-

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