4.1.42D Graphics Options

The display driver support options to control 2D rendering. Some of these also affect video rendering.

[HKEY_LOCAL_MACHINE\Drivers\Display\Intel]

SysToVidStretch <DWORD>

This key determines if the system to video stretch BLT functionality is enabled in the driver.

0 = disabled

1 = enabled

BlendFilter <DWORD>

This key determines the blending filter used for 2D stretch BLTs via GDI stretch BLT and DirectDraw AlphaBlt routines. It only affects GDI stretch BLTs when the GDI stretch blit mode is set to BILINEAR through the SetStretchBltMode GDI API. It only affectsAlphaBlt-based stretch blits when the DDABLT_FILTERENABLE flag is used.

1 = Bilinear

2 = Anisotropic

BlitSyncVBI <DWORD>

This key determines if a 2D BLT operation will be blocked until the vertical blanking interval before executing. The BLT occurs during the vertical blanking period, which updates the frame buffer when active data is not being displayed. This can be used to prevent tearing if BLT operations are being requested directly on to the primary frame buffer.

Note: This key enabled for GDI only, not DirectDraw – If DirectDraw is used, double buffering should be used to accomplish this because flipping the back buffer on-screen will sync to the vertical blanking interval automatically. Flipping will utilize less CPU than using BlitSyncVBI because BlitSyncVBI busy waits for the vertical blanking interval within the display driver, whereas flipping is asynchronous.

0 = disabled

1 = enabled

InterlacedToProgressiveAutoBob <DWORD>

This key determines whether hardware bob will be automatically enabled for overlays if interleaved (woven) source is provided and the GMCH is in a progressive display mode. If this key is disabled, hardware bob will not be automatically enabled for overlays.

Note: The driver dynamically checks the state of this registry key value whenever

IDirectDrawSurface5::UpdateOverlay is called to show the overlay.

Note: This registry key value is only supported on the 830 and 854 GMCH.

0 = disabled

1 = enabled (default)

18Intel® Digital Set Top Box Display Driver User’s Guide for Microsoft* Windows* CE 5.0

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Intel 82830M GMCH, 82854 GMCH manual 4 2D Graphics Options, SysToVidStretch Dword, BlendFilter Dword, BlitSyncVBI Dword

82830M GMCH, 82854 GMCH specifications

The Intel 82854 GMCH (Graphics Memory Controller Hub) and the Intel 82830M GMCH are integral components in the architecture of Intel's mobile chipsets, designed to enhance performance and efficiency in laptop and portable computing environments. These chipsets play a crucial role in managing the interactions between the CPU, memory, and graphics, thus impacting overall system performance.

The Intel 82854 GMCH, launched as part of the 855 chipset family, primarily targets mobile laptops and portable devices. A key feature of the 82854 is its support for DDR SDRAM, which improves memory bandwidth and enhances data transfer rates. This chipset is also notable for its integration of graphics capabilities through Intel Graphics Media Accelerator 900. This integration allows for better power management and reduced physical space requirements, making it suitable for compact laptop designs.

Another significant characteristic of the 82854 GMCH is its support for Intel SpeedStep technology, which optimizes power consumption by dynamically adjusting the processor voltage and frequency according to the workload. This capability is essential for prolonging battery life in portable systems without compromising performance during demanding tasks. The chipset also includes support for up to 2GB of memory, catering to the requirements of most mobile applications at the time of its release.

The Intel 82830M GMCH, on the other hand, was part of the 855PM chipset family and is targeted primarily at mainstream laptops. It offers similar features in terms of integrated graphics with the Intel Graphics Media Accelerator. However, it also extends support for advanced features such as the 533 MHz front-side bus, which facilitates quicker data transfer between the CPU and memory.

Key technologies associated with the 82830M GMCH include the Enhanced Intel SpeedStep Technology, which further enhances power management capabilities beyond earlier iterations. By incorporating this technology, the chipset maximizes energy efficiency during various operational states, ensuring that users enjoy longer battery life without sacrificing system performance.

Both chipsets support PCI Express connectivity, providing a pathway for high-speed communication with other peripherals, improving overall system responsiveness. The integration of these technologies into the 82854 and 82830M GMCH models has made them integral to the development of mobile computing, allowing for powerful yet efficient laptop designs that meet the needs of users on the go.

In summary, the Intel 82854 GMCH and 82830M GMCH are foundational components that showcase Intel's commitment to enhancing mobile computing through robust memory and graphics management, advanced power-saving technologies, and seamless integration with modern peripherals. Their influence extends through the generations of mobile devices, reflecting the ongoing innovations within Intel's chipset developments.