Although the minimum system requirement for Inventor 2010 is 1GB, you should always consider adding as much RAM as you can afford to your workstation. If making the move to a 64-bit system, you will require a minimum of 4GB of RAM, and you should consider at least 8GB.

To ensure that your graphics card is set at the optimal settings, select the Tools tab, click Application Options, and go to the Hardware tab in the dialog box that opens. Direct3D graphics hardware is the default setting for Windows XP Professional 32-bit and 64-bit versions as well as Windows Vista 32-bit and 64-bit versions.

Inventor 2010 will use either OpenGL or the default DirectX 9 hardware acceleration modes when running Windows XP. Windows XP 64 uses DirectX 9 only. Windows Vista 32 and 64 support DirectX 9 and 10. Inventor will automatically detect the appropriate level for your card. All configurations have OpenGL software emulation.

It is recommended that you consider a midrange graphics card for an Inventor workstation and save the money for frequent upgrades rather than investing in a high-end card, because of the rapid changes in video card technology. For recommendations on graphics cards and other hardware, refer to the following websites:

Inventor files are segmented, meaning that the graphics are separate from the feature information. When an assembly is first opened, only the graphics segments are loaded. When you edit a file, the additional data is loaded at that time. This makes a fast hard drive important for performance.

Another aspect of hard drive performance stems from file storage and workspace setup. In Inventor, working from your local drive is the preferred method, and Autodesk recommends you avoid working on Inventor files across a network. The reason for this is simply because of the numbers of files that you might be editing at one time. For instance, a change to a large assembly could potentially modify hundreds of part files, requiring all those files to be saved at once. Doing this across a network, particularly one with latency issues, may result in file corruptions if the files are not saved correctly. Autodesk Vault is set up to store files on a server and copy those files locally when checked out for editing. When working in this manner, Inventor has a higher-performance requirement than standard office applications, and the hard drive workload is very heavy. Therefore, upgrading your hard drive to a higher-speed SATA or serial attached SCSI (SAS) drive may be worth considering.

When considering processors for an Inventor 2010 workstation, the chief question should concern multicore processors. As a minimum, you should consider a dual-core processor even though Inventor is not truly a multithreaded application. (Multithreaded means that the operating system or the application will spread the processing load across the processor.) If you opt for a dual-core processor, you can still take advantage of it, because Inventor will run on one core and other applications will run on the other.

There are parts of Inventor, such as Inventor Studio's rendering engine, that are multithreaded, so if you plan to do a lot of image and animation rendering in Inventor, you may want to opt for a quad-core processor. Otherwise, if you are trying to decide between a dual-core and quad-core processor, it will probably be more cost effective to go with a faster dual-core processor rather than a quad-core processor. This will likely change as the rapid pace of technology continues.

The Display Line Weights check box enables or disables the display of unique line weights in drawings. Deselect the box to show lines without weight differences. Line weights will still print correctly even with this box selected. Deselecting this box will speed up the performance of your drawing during edits and annotation work.

The options in the Show Preview As drop-down box set the type of preview you get when creating a view. All Components is the default, but you will find that selecting the Partial or Bounding Box option will improve performance because Inventor will not be required to create and update the preview as you drag your mouse pointer around the screen. The preview setting does not affect the drawing view result. Bounding Box previews a simple rectangle during the view creation, and Partial previews a simplified representation of the view. Bounding Box is the most efficient.

When using this option, you can still preview the assembly if you'd like by simply selecting the Preview check box in the Drawing View creation dialog box, but the default will be a simple bounding box. Using the Bounding Box option is suggested if you find yourself waiting for the preview to generate during drawing view creation.

The Section View Preview As Uncut check box will also provide some performance improvements when selected. This option will allow Inventor to display the section view preview as unsectioned in order to be more efficient. The section view will still be generated as normal.

Memory Saving Mode sets the way that Inventor loads components into memory during view creation. When this option is selected, Inventor loads components into memory before and during view creation and then unloads them from memory once the view is created.

Although memory is conserved using this mode, view creation and editing operations cannot be undone while this option is enabled. You'll notice the Undo/Redo buttons will be grayed out after a view creation or edit. This option will also have a negative impact on performance when editing and creating views because the components must be loaded into memory each time. Because of this, you should consider setting this option as an application setting only if you always work with very large assemblies.

It is generally preferred to set this option per document by selecting the Tools tab, clicking Documents Settings, going to the Drawing tab in the dialog box that opens, and then setting the Memory Saving Mode drop-down list to Always, as shown in Figure 9.2.

Also in the document settings, you can adjust the way that shaded views are displayed. Setting the Use Bitmap drop-down list to Always, as shown in Figure 9.2, improves performance by applying raster shading as opposed to a vector style. The difference impacts the display but typically does not affect printing.

You can also adjust the bitmap resolution; setting it lower conserves memory and speeds up performance. The default is 100 dpi. Setting the dpi to 200 or higher will invoke a prompt, warning you that increasing this setting for large assemblies may not be possible.

Deselecting the Edges check box for Enabled components in the Shaded Display Modes area of the Display tab will lighten the amount of graphics rendering required to display and update the display of your large assemblies.

Setting the Display Quality drop-down list to Rough, as shown in Figure 9.3, will speed up performance by simplifying details. Navigation commands such as zooming, panning, and orbiting are particularly affected by this setting. If you find that the rough display is not to your liking, you can toggle back and forth according to the size of the assembly model you are working with.

The View Transition Time (Seconds) setting controls the time required to smoothly transition between views when using zooming and viewing commands. A zero transition time takes you from the beginning view to the end view instantaneously. For instance, if you were zoomed in on a small component and wanted to zoom all while this slider was set to zero, you would not see the gradual zooming out that may provide a gain in performance but can make changes in position and orientation less clear.

Figure 9.3. The Display tab in the Application Options dialog box

You can use the Minimum Frame Rate (Hz) setting to specify how slowly the display updates during zooming and orbiting commands. It may be hard to see the effects of this option on a normal-sized part or assembly, because the views will typically update more quickly than the rate of this setting. Here is a quick description of the how the slider setting corresponds to the frame rate:

The Enable Optimized Selection setting, located on the lower-right corner of the dialog box, improves the performance of graphics during prehighlighting in large assemblies. When activated, the algorithm for the Select Other function filters for only the group of objects closest to the screen. If you click through this first group of objects, the next group is considered for highlighting.

When checked, the Update Physical Properties On Save setting, located in the Physical Properties area on the right side of the dialog box, recalculates the mass properties of the model when you save the file. This ensures that mass properties are up-to-date. Setting this to Parts Only will ensure that the parts are all up-to-date without requiring you to wait on the recalculation for large assemblies. Note that this setting is disabled altogether by default but is recommended to be set to Parts Only if you find it helpful. Note too that the same function can be performed manually from the Bill Of Materials Editor and the Manage tab.

The Undo File Size option, on the lower-right side of the dialog box, sets the maximum size of the temporary file that records changes to a file so that actions can be undone. It's typically required to increase the size of this setting when working with large models and drawings, because each undo action is typically a larger calculation. Autodesk recommends adjusting this in 4MB increments.

The Capacity Meter is displayed at the bottom-right corner of the Inventor screen, as shown in Figure 9.5. The meter has three memory use indicators. The number to the left is the total number of occurrences in the active document. The next number is the total number of files open in the Inventor session. The last indicator is a colored bar graph that displays the amount of memory used by the session. When hovering your mouse pointer over the Capacity Meter, a tool tip will display the details of used and available memory. In 32-bit systems, you can use the meter in two modes: Inventor Only and Physical Memory. In 64-bit systems, the Inventor Only mode is not available.

Figure 9.5. Capacity Meter in Inventor Only mode

On 32-bit systems the Capacity Meter display is set to look at just the Autodesk Inventor process. The bar color will change from the normal green to yellow when more than 60 percent of the allotted address space has been used. It will then turn red at 80 percent, and a warning dialog box will prompt you to close documents in an attempt to free up memory, as shown in Figure 9.6.

Figure 9.6. Warning received at 80 percent capacity

As a rule, you should not habitually work when the meter indicates that you have passed the 60 percent mark. When you do see the bar turn yellow, you should stop and create an LOD representation or close some files. LOD representations are covered later in this chapter. Working in limited memory can lead to memory corruptions in the file and result in a loss of work.

Typically what happens when a user continues to work past the 60 percent range is that some memory-intensive calculation is performed that will cause the virtual memory to fill and then have to "swap" out a large amount of data. During this time, your system may become unresponsive and any well-intentioned attempt to help may cause file corruptions.

Other common results of working past the 60 percent marker occur when saving or creating a drawing view. When working in this manner, it is possible to reach a point at which you will not have enough memory available to save the files. The same can happen when attempting to create drawing views of an assembly when you have reached this marker.

Therefore, you should not work past the 60 percent marker, other than to create LODs and/or to take other actions to reduce the amount of memory your file is requiring.

On 64-bit systems the Capacity Meter display indicates the entire system's RAM. The green portion represents the Inventor session, while the yellow portion is all other applications. This mode is disabled if you do not have administrative rights on your workstation or if process monitors have been restricted on your system.

To change the size of the virtual memory paging file in Windows XP Professional, right-click the My Computer icon, and choose Properties. On the System Properties tab, click the Advanced tab, then click Performance Options, and finally under Virtual Memory click Change.

In Windows Vista, right-click the Computer icon, and choose Properties. On the System Properties tab, click the Advanced System Settings tab, then click Performance Options, and finally under Virtual Memory deselect Automatically Manage Paging File Size For All Drives. Then click Change.

Select Custom Size, set the Initial Size and Maximum Size settings to twice the available RAM, and click Set, as shown in Figure 9.7.

Figure 9.7. Setting the page file size in Windows XP

Windows provides many options to set the visual effects of your computer. Many of them have a surprisingly high impact on performance when memory is scarce. Here are a few you might consider disabling in order to conserve resources:

Too many cross-part adaptive features can cripple the performance of even a modest-sized assembly if used without discretion. As discussed in Chapter 8, adaptivity should generally be turned off once the adaptive feature or part is created.

Often features and parts are made adaptive during the early design stages of a model, when changes are made quickly and you want many parts to follow these changes. Turning off the adaptive status in the part ensures that your assembly performance will not be affected. If the adaptive part needs to be edited, you can turn on its adaptive status so that you can make adjustments.

Many times parts become adaptive by default when creating a new part or feature in an assembly because a reference sketch is projected from one part to another. You can disable this by going to the Tools tab, clicking Application Options, going to the Assembly tab in the dialog box that opens, and then deselecting the Enable Associative Edge/Loop Geometry Projection During In-place Modeling option under Cross Part Geometry Projection. This will create fewer accidental adaptive parts but may require more manual effort in projecting geometry across parts.

When working with a large assembly, combing through all the many parts within that assembly that you want to select for a given task can be time-consuming and difficult if you attempt to locate them using the standard Pan, Zoom, and Orbit methods. Instead, make yourself familiar with the options in the assembly selection tool.

You can use selection tools to suppress sets of components based on such factors as size or on internal components that are not visible because of the presence of external housings, and so on. For instance, to maintain performance, you may not want to load all the internal components into memory when they are not important to your current design task. Once you've selected the internal components, you can suppress them and create an external part-only LOD representation.

Another use of assembly selection tools is to create view representations in the assembly to aid in the creation of views in the drawing file. As an example, when you place a view in the drawing using a design view that was created using the All In Camera tool, only the components in the screen view plane are calculated. This increases performance and memory capacity. Figure 9.11 shows the available selection tools.

Figure 9.11. Available selection tools

The following are the selection tools:

View representations are often used in large assemblies to navigate to a predefined viewing angle so that you do not have to tax your system with heavy graphics regeneration. For instance, if you have an assembly that contains an entire production line of material-handling equipment, you may find it difficult to orbit around to the backside of the assembly in order to complete a simple task such as selecting a face or just looking at the assembly. If you set a design view before orbiting and then set another once you have orbited to the desired view, you can then easily toggle between the two views of this assembly, thereby increasing performance during navigation between these predefined views.

View representations have other large assembly benefits as well. When creating a drawing view of a large assembly, you can specify a preset view representation and reduce the time it takes to create the drawing view. If you have turned the visibility of some components off in the assembly view representation, the drawing view can generate even faster and provide you with a clearer and more concise view. Of course, if you already have the assembly open when creating the drawing view, the components are likely already loaded into memory.

Another way that the experienced Inventor user may use view representation is to navigate the Model Browser. For instance, if you set up a view representation to zoom in on a particular subassembly so that you can navigate to that component quickly, you can save that view representation while the entire model tree is rolled up and only the subassembly of interest is expanded. This browser state will be saved within the view representation.

Once a view representation is created, you can right-click it and choose Copy To Level Of Detail to copy the view representation to an LOD representation. This allows you to transfer the visibility settings from the view representation to the LOD where they will be suppressed. In this way, you do not have to duplicate the process of turning parts off.

Navigating a large assembly Model Browser can be a chore. To help with this, you can employ the Find tool to define search criteria for constraints, components, features, sketches, and welds. Searches can be saved for future use and recalled as needed using the Open Search button, as shown in Figure 9.13.

Figure 9.13. The Find tool in an assembly file

You can access the Find tool in the following ways:

When creating drawing of large assemblies, it is advised that you do so from an LOD representation already created in the model. Doing so reduces the number of files Inventor is required to access to create and update the line work in the view. To create views from assembly representations, you simply specify the representation(s) you want to use in the Drawing View dialog box, as shown in Figure 9.15. Keep in mind that when browsing for the file to create a view of, if you use the Options button in the Open dialog box to specify the representation, you will reduce the time it takes to create the view.

Figure 9.15. Creating a drawing view from an LOD

Hidden line generation can be one of the most memory-intensive aspects of creating a drawing view. Generally, with large assemblies, it is not desirable to show the hidden lines of all components. Instead, you typically will want to enable hidden lines for just those components where hidden lines add clarity.

Rather than selecting the Hidden Line style in the Drawing View dialog box, first create the view with no hidden lines. Next locate and expand the view you just created in the browser, and select the components you intend to be shown with hidden lines. Right-click the components, and choose Hidden Lines.

You will be prompted with a message box informing you that you are changing the view style to show hidden lines and that any children of this view will be granted an independent view style based upon their current setting, as shown in Figure 9.16. The result will be that only the components you chose will be displayed with hidden lines.

Figure 9.16. Managing hidden lines

A sure way to slow down your drawing's performance is to create an unnecessarily complex title block. If you have included a bitmap of your company logo in your title bock, ensure that the bitmap file is reduced in resolution and file size as much as possible. You can use any photo editor to do this.

Once you've reduced the bitmap file as much as possible, consider embedding the file into the title block rather than linking it. Although linking the bitmap does give you greater flexibility in updating the logo independent of the title block, Inventor will be required to locate the bitmap each time the drawing is loaded. To embed rather than link the logo bitmap, simply deselect the Link check box when inserting the bitmap.

If you have pasted the logo in from AutoCAD, ensure that the logo is as clean as possible. You may be better off removing the hatches from the logo in AutoCAD and then adding them using the Fill/Hatch Sketch Region tool in Inventor.

Although it is possible to create a large number of sheets in a single drawing file, it is generally accepted that this is not good practice. Instead, you should consider making a new file for each drawing sheet when possible. Or at the very least, keep the number of sheets per file as low as possible. There are two primary reasons for doing this.

The first reason is simply to keep the file size down. If you have a drawing of a large assembly file that includes four sheets and has a file size of 80MB, you could spilt this into two files, each with two sheets and a file size of approximately 40MB. In this way, you do not have to load the extra 40MB in sheets 3 and 4 just to make an edit to sheet 1.

The second reason to minimize drawing sheets is so you are not guilty of placing "all your eggs in one basket." Creating multiple tab or sheet files in any application can be risky. Imagine you created a load calculation spreadsheet and you developed the habit of adding a tab for each new calculation you do, rather than creating a new file for each calculation. If the file becomes corrupt, you've lost all your calculations rather than just one set of calculations. The same thing could happen with your Inventor drawing if you habitually create new sheets instead of new files.