Graphics
Mobile Intel® 945GM Express Chipset Family
Multi-Monitor: Understanding options for multiple displays


What is Multi-Monitor?

The existence of multiple display devices on a single system gives the user a number of possible configuration options. For example, two devices can be driven independently with different content, resolutions and color depth on each in order to increase desktop space. Another possible configuration sends the same content to different monitors to give a presentation to a large audience.

Multi-Monitor Support on the Mobile Intel® 82945G Graphics and Memory Controller Hub (GMCH)

Microsoft Windows* 2000. Windows* XP, and Windows Vista* operating systems have enabled support for multi-monitor display. Since the Mobile Intel® 82945G Graphics and Memory Controller Hub (GMCH) has several ports available for its two pipes, it can support up to two images on different display devices. Timings and resolutions for these two images may be different. The Mobile Intel® 945GM Express Chipset Family supports Intel® Dual Display Clone and Extended Desktop.

Note: The GMCH graphics engine is incapable of operating in parallel with an external PCI Express* graphics device. The GMCH graphics engine can, however, work in conjunction with a PCI graphics adapter.

Multi-Monitor Option: Intel® Dual Display Clone

  • Intel Dual Display Clone is used to drive multiple displays with the same content.
  • Intel Dual Display Clone is beneficial when using displays of various types and sizes, such as one pipe driving an integrated LCD, while the other pipe drives an analog overhead projector that may only sync to particular resolutions and refresh rates.
  • To activate Dual Display Clone (See Figure 1): Open the Intel® Graphics Media Accelerator Driver for Mobile window. This window can be opened by--
    • pressing Ctrl Alt F12 (simultaneously), or
    • right-clicking on Windows* desktop and selecting Graphics Properties, or
    • opening Windows* Display Control Panel and selecting Settings » Advanced » Intel(R) Graphics Media Accelerator Driver for Mobile » Graphics Properties.
    Enable the Intel(R) Dual Display Clone setting in the Display Devices section. Choose which device will be the Primary Device and which one will be the Secondary Device. Then click Apply.



    Figure 1: Intel® Dual Display Clone Setting


Multi-Monitor Option: Extended Desktop

  • Extended Desktop refers to the ability of a single adapter with at least two display pipes to support multiple monitor configurations.
  • One important use for multi-monitor is to allow for a large Windows* desktop that spans multiple displays, which creates more screen real estate than a single display provides.
  • The Display icon in Windows* Control Panel or the Display Devices section of the Intel® Graphics Media Accelerator Driver for Mobile window can be used to configure the size and relative position of each monitor. (See Figure 2.)
  • Applications can be moved from one monitor to another, or can be on more than one monitor simultaneously.
  • To activate Extended Desktop, open the Intel® Graphics Media Accelerator Driver for Mobile window. This window can be opened by--
    • pressing Ctrl, Alt, and F12 keys at the same time or
    • right-clicking on Windows* desktop and selecting Graphics Properties, or
    • opening Windows* Display Control Panel and selecting Settings » Advanced » Intel(R) Graphics Media Accelerator Driver for Mobile » Graphics Properties. Enable the Extended Desktop setting in the Display Devices section. Choose which device will be the Primary Device and which one will be the Secondary Device. Then click Apply.




    Figure 2: Extended Desktop Setting

  • Display output options may also be enabled directly from the Windows desktop. Right-click on a blank area of the desktop to access the Graphics Options menu. The output options will be listed. (See Figure 3).



    Figure 3: Graphics Output Options as seen on the Windows* Desktop
  • Applications may behave differently in a multi-monitor configuration depending on their implementation:
    • Standard Windows applications that use the GDI (Graphics Device Interface) will clip the window to each display and accelerate the images separately using the display hardware.
    • Applications that span multiple monitors and use Microsoft DirectX*, Direct3D* or DirectDraw* will be software accelerated.
    • OpenGL* applications may exit unexpectedly, hardware accelerate one display with unknown results on the other or be software accelerated.
    • A full screen command prompt or MS-DOS* application will only function on the Primary Display Device.


Computer Requirements for Multi-Monitor

  • A computer based on integrated Mobile Intel® 945GM Express Chipset Family that has dual pipe enabled by the computer manufacturer
  • Two or more display devices (such as notebook display, DVI, TV, analog monitor, external flat panel, etc.)
  • Microsoft Windows* 2000, Windows* XP, or Windows Vista*
  • The Intel® Graphics Media Accelerator Driver is installed.


Related Topic
Mobile Intel® 945 Express Chipset Family Datasheet
How do I get the latest graphics driver?

Operating System:
Windows XP Professional x64 Edition*, Windows Vista 64*, Windows Vista*, Windows Vista 32*, Windows 2000*, Windows XP Professional*, Windows XP Home Edition*

This applies to:
Mobile Intel® 945GM Express Chipset Family

Solution ID: CS-022119
Date Created: 28-Dec-2005
Last Modified: 17-Feb-2010
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