Information about:

  • AutoCAD R14 and 2000
  • Mechanical Desktop 3.0, 4.0
  • and more!

  • Contents:

    Visual Workstation Configuration Information:

    It is very important to properly configure the Visual Workstation graphics and display settings for the Autodesk products. Some of these settings have no direct affect on the applications, but make the system work better in general. All these settings are contained on the "Display Properties" control panel.

    1. First, be sure the Enable SGI and DCC Video Modes option is enabled in the Silicon Graphics Display panel.
      1. This enables additional video modes and resolutions with SGI monitors.
      2. In fact, all SGI-PC monitors I've tested seem to support the 1920x1200 mode, which gives amazing desktop real estate.
      3. Be aware, however, that this means your system has to update significantly more pixels than at lower resolutions.
        1. For benchmarking purposes, be sure to set a resolution to something comparable to the competition.
    2. Next, go the the "Silicon Graphics Settings" panel and select the "CAD Design" profile from the list of pre-defined graphics profiles and then select the "Copy" button. You can rename the resultant profile as you like, but the important thing is that this makes the settings modifiable by you. Now hit the Properties button and you can see what the settings are.
      1. The Screen Area controls the size of the video display based upon the monitor's capabilities (see #1 above).
      2. Refresh Rate is tied to the video monitor capabilities as well.
      3. Color Palette controls the "depth" of the video frame buffer.
        1. For AutoCAD and Mechanical desktop, use either 32768 Colors or TrueColor for best performance.
        2. If you are not using the AccelGraphics OpenGL viewer or Mechanical Desktop (which includes the AccelGraphics viewer) you might try the 256 color option to save memory if desired.
      4. The Depth Buffer setting should be set to either 16 or 24 bits for Mechanical Desktop (or AutoCAD w/ AccelGraphics viewer) otherwise, it can be turned off to save memory.
      5. Graphics Options should be set to Use Back Buffer if using the AG viewer or Mechanical Desktop, otherwise, both can be turned off to save memory.
      6. Graphics Memory Allocation can be set to 0 for Autodesk CAD products, as they use no texture mapping features that require additional graphics memory.
    3. These steps must be done for each and every user account on the system who will be using the software. This is because this information is stored on a per-user basis.
      1. The default system configuration is not ideal for running Autodesk software, it must be changed.


    1. You must base your changes off of the CAD Design profile and nothing else.
      1. If you are unsure what you have based your profile from, delete it and make a copy of the CAD Design setting.
    2. You must reboot your system after making these changes.

    Since the Visual Workstation makes use of the Integrated Visual Computing (IVC) architecture , all the graphics memory needs are supplied from the total memory installed in the system. Thus, going from 32768 colors (which uses 2 bytes of memory per pixel) to TrueColor (which uses 4 bytes per pixel) doubles the amount of RAM used for the frame buffer. Likewise, enabling back buffer support doubles memory use again (a copy for the front buffer and a second copy for the back buffer). Increasing the screen resolution increases the memory use as well. So there is always a tradeoff in how much memory to allocate to the graphics and how much to allocate for the system. It is best to allocate as little as needed to the graphics to allow the hardware to support the application(s) needs. Otherwise, if the hardware can't support a given mode, a much slower software path will be used. For example, if the application request double-buffer graphics, but the hardware double-buffer support is disabled, the software rendering engine will provide a second buffer but speeds will be perhaps 1/20th that of the hardware path.

    Conversely, allocating too much memory to graphics such that the application begins to page to disk, is not a good idea either. If no applications use texture mapping, then allocating memory for texture storage is a waste. If you are running multiple applications, then choose the graphics settings required by the most demanding application. The settings set an "upper limit" of capabilities that the hardware driver can provide. Setting capabilities too low, results in a much slower software path, setting too high wastes memory.

    Below, is a summary of the minimum and recommended graphics settings for these Autodesk (and Kinetix) applications. Under each application are its minimum requirement and the recommended column indicates a setting that will work for all the applications.

    Setting AutoCAD R14 (2) AutoCAD 2000 (2) Mechanical Desktop v3 (2) Mechanical Desktop v4 (2) 3D Studio Max Recommended
    Color Palette 256 16M 32K 32K/16M 32K/16M 16M
    Depth Buffer None(1) 24 Bit Depth
    /8 Bit Stencil
    16 Bit Depth 16 Bit Depth 24 Bit Depth 24 Bit Depth
    8 Bit Stencil
    Enable Overlay Planes Yes Yes Yes Yes Yes Yes
    Use Back Buffer No(1) Yes Yes Yes Yes Yes
    Graphics Memory Allocation 0 0 0 0 As needed by model As needed by model
    Visual Workstation Graphics Settings


    1. For use w/ standard product, if using the AccelGraphics viewer, see Mechanical Desktop settings
    2. If you are using the 4.1 Cobalt graphics driver (recommended), then right-click on the application links to download graphics profiles customized for that application
      1. Then, load the profile with the new Display->GraphicsSettings Control Panel

    AutoCAD R14 Information:

    Nothing special needs to be done for the base level product. It only makes use of GDI (native Windows) rendering features, 256 colors is sufficient for basic 2D drafting, more colors may be useful for rendered images.

    NOTE: If you are using AutoCAD R14 in conjunction with an IRIX server running the Samba file services, you should install the following patch for AutoCAD to avoid potential file access problems.

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    Mechanical Desktop 3.0 Information:

    Mechanical Desktop 3.0 is a product layered on top of AutoCAD R14. If you want to enable the special Mechanical Desktop 3D features, be sure to launch the application form either the shortcut named "AutoCAD Mechanical X.XX" or "Mechanical Desktop X" and not "AutoCAD R14 ...", otherwise you'll get just the plain AutoCAD feature set. Note, launching the application by double-clicking on a .DWG file unfortunately launches a vanilla AutoCAD session. Best to start the application from the desktop shortcut then open the drawing from the application's File->Open menu.

    Once opened, the Mechanical Desktop 3D features are available from the floating Desktop View palette. The buttons from left to right are:

    Of particular interest is the toggle shading button. Clicking it once transforms the drawing to shaded mode (if it contains shadeable 3D data). Then the Dynamic Rotation is very nice for rotating the model, in shaded mode. However, once the enter button is pressed, a slow REGENerate command is executed before editing may continue. The Pan and Zoom modes operate in either shaded or wireframe mode, don't cause a REGEN, but when active, they enter a wireframe mode regardless of the current shading mode.

    The AV3DVARS command will bring up a display dialog that will allow fine-tuning of the viewer.

    Changes the user-configurable 3D display options. At the Command prompt, enter av3dvars and the 3D Graphics Preferences dialog box is displayed.


    IMPORTANT: There is one potential problem in using this feature that must be understood and possibly worked around. The problem is that the AccelGraphics OpenGL viewer that is used for the 3D portion of Mechanical Desktop installs a custom "software" cursor while rotating the model. Unfortunately, this adds a significant overhead to OpenGL rendering to manage this cursor, meaning that OpenGL rendering on the 320 tops out at about 5 frames per second or so. This overhead, fortunately, is somewhat fixed, so that the larger the model, the more it is hidden. In other words a 100 polygon model or a 100,000 polygon model will display at approximately the same frame rate. Therefore, it is important to demo this feature with a large model (or get the

    NOTE: If you are using AutoCAD R14 in conjunction with an IRIX server running the Samba file services, you should install the following patch for AutoCAD to avoid potential file access problems.

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    AutoCAD 2000 Information:

    Wonder what ever happened to AutoCAD R15? Well, it got the Y2K bug and thus you now have AutoCAD 2000 (aka A2K :-).


    Yes, it seems to work very well, thank you.


    Does it support multiple processors? Alas, multi-threading remains on the to-do list for a future version of AutoCAD. Here's what Autodesk says about this issue:
    "AutoCAD 2000 will work fine with dual processor machines, and you'll see some performance gain because Windows NT assigns multiple applications to different processors."


    Yes, but not by default.

    To enable OpenGL, you need to do the following steps:

    IMPORTANT: You will also need to ensure some stencil buffer support is reported by the graphics driver in order for the OpenGL capabilities to be properly recognized by the application. Stencil buffer is tied in with the 24 bit depth buffer, so be sure this option is selected int eh Silicon Graphics Graphics settings panel.

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    Mechanical Desktop v4.0 Information:

    Mechanical Desktop v4.0 is a layered product on top of AutoCAD 2000. Most of the above A2K issues apply to Mechanical Desktop v4.0. Also some of the Mechanical Desktop 3.0 issues apply, but fewer. However, there are some significant differences with the MDT4 product that are important to consider:


    Yes, but not by default.

    To enable OpenGL, you need to do the following steps:

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    [Last updated: 18.JUN.1999]