2011

Table Of Contents
Maintain Compatibility with Large Object Limits
Drawings saved to a legacy drawing file format (AutoCAD 2007 or earlier) do
not support objects greater than 256MB. With the AutoCAD 2010 drawing
file format, these limitations have been removed allowing you to save objects
that are greater in size.
When saving to a legacy drawing file format (AutoCAD 2007 or earlier), the
drawing cannot contain large objects; there might be compatibility issues with
trying to open the drawing. The LARGEOBJECTSUPPORT system variable
controls the large object size limits used and the warning messages displayed
when a drawing is saved.
The following explains how object size limits for drawings is determined:
Drawing files cannot exceed an internal size limit of 4GB. This size is based
on the total size of all objects in a drawing when uncompressed. Since a
drawing file is normally compressed, the final size of a saved drawing file
on disk will vary based on the size and number of objects in a drawing.
Each individual object in a drawing cannot exceed an uncompressed size
limit of 256MB. For example, a mesh object, when saved to a file and
compressed, might be 75MB in size while the same object when
uncompressed might be 257MB.
In these situations, the drawing cannot be saved to an AutoCAD 2007 or earlier
file format until the issues are resolved. You can resolve the size limits by
breaking the drawing or objects up into several drawings or objects.
NOTE When working with the 64-bit release of AutoCAD, you can work more
efficiently with large objects and drawings. However, the drawing files you create
might be too large to open with the 32-bit release of AutoCAD.
See also:
Save Drawings to Previous Drawing File Formats on page 1822
Work with Drawings in Earlier Releases on page 1817
Export Drawings to Other File Formats on page 1802
Create Drawing Files for Use as Blocks on page 867
Add Identifying Information to Drawings on page 174
Create and Restore Backup Files on page 210
200 | Chapter 7 Open or Save a Drawing