About Large Object Limits and Drawing File Compatibility

Drawings saved to legacy drawing file formats (2007 DWG format or earlier) do not support objects larger than 256MB. The 2010 DWG format removes this limitation.

The LARGEOBJECTSUPPORT system variable controls the object size limits and the warning messages displayed when a drawing is saved.

If either of the following limits are exceeded, the drawing cannot be saved to a 2007 DWG format or earlier drawing file format until the issues are resolved. Resolve the size limits by breaking the drawing or objects up into several drawings or objects.
Note: When working with a 64-bit release, you can work with large objects and drawings more efficiently. However, the drawing files you create might be too large to open with a 32-bit release version of the same product.