TITLE
    iMac: Graphics Acceleration Limited By VRAM Configuration
Article ID:
Created:
Modified: 		30693
8/11/98
6/20/00
TOPIC

    I purchased some games that can use the iMac's hardware graphics acceleration, but they behave as if 3D acceleration is not available. Can you explain?

DISCUSSION

    The original Bondi Blue iMac ships with 2 megabytes of VRAM, a configuration that allows 3D acceleration only at the lowest resolution, 640 x 480. Either reduce the resolution or install more VRAM (SGRAM).

    Beginning with the 266 MHz iMac, VRAM was increased to 6 MB. Check the technical specifications, or use Apple System Profiler to determine what quantity of VRAM is installed.

    To determine whether the iMac has more than 2 MB of VRAM installed, open the Monitors & Sound control panel and select the 1024 x 768 resolution shown. If "Millions" is an option provided in the "Color Depth" section of the control panel, the VRAM has been upgraded.

    Other reasons why 3D acceleration may not be available:

    • The program may have installed extensions or other software of its own that did not load prior to running the program. Check with the program's documentation or manufacturer to confirm what software is required and where it should be installed.
    • When the program was installed, it may have replaced the iMac's existing ATI extensions with older versions. The following extensions enable video, graphics, and 3D acceleration on the iMac:
      • ATI Video Memory Manager
      • ATI Video Accelerator
      • ATI Graphics Accelerator
      • ATI 3D Accelerator
      Without them, or with older versions of them, acceleration may not become enabled.

Document Information
Product Area: iMac
Category: iMac Hardware
Sub Category: General Topics

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