SGI Windows NT Toolbox

KnowledgeBase

Display Memory on the Visual Workstations


System:   any Category:   graphics Last Modified:   2/22/99
OS version:   NT 4.0 Product:   OpenGL Service Pack:  
Description

What is display memory, and how would I change the amount available to graphics applications?

Problem Resolution

The Silicon Graphics 320 and Silicon Graphics 540 Visual Workstations are based on the Integrated Visual Computing (IVC) architecture, developed by Silicon Graphics. What this means is that, unlike most PCs, display memory is shared with system, or "CPU memory." This architecture has major advantages over traditional PC architectures, some of which include:

  • fewer and faster buffer-to-buffer copies
  • virtually unlimited texture memory
    (limited only by the amount of memory installed in the machine)
  • more flexibility
  • speedy advanced rendering involving off-screen buffers,
    for such effects as reflections and live video
  • less expensive machine
The amount of memory dedicated to graphics may be customized on the Silicon Graphics 320 and the Silicon Graphics 540 to suit the type of application being run. For example, applications such as flight simulation might require a fair amount of display memory for storing hundreds of textures for land features, trees, etc. Image processing applications may want to allocate more memory to be used in off-screen image processing.

To change the amount of available memory, bring up the Display Properties panel:

  1. Choose Start->Settings->Control Panel
  2. Select Display
Or, a quicker method:
  1. Right-click on the background of the screen to reveal a pop-up menu
  2. Select "Display Properties"
    Then, from the "Display Properties" panel, select the <Silicon Graphics Settings> tab panel.
There are several recommended settings, based on estimated memory demands. Your application may need more or less than the recommended amount. You can choose one of the recommended settings, then customize it by using the "copy" button.

Keep in mind that any memory allocated here will be subtracted from the pool of memory available to Windows NT. For example, if you have 512 megabytes installed and you allocate 128 megabytes for graphics memory, Windows NT will see only 384 megabytes of memory when it boots. In most cases, you will need to reboot for the changes to become active.


Send comments on this case to kbase@sgi.com.


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