File Size Limits 

FACT's major shortcoming is its performance editing large files.  General text editing continues to work acceptably as the file gets larger, but the process of adding elements, in particular adding (or editing) components, can be insufferably slow.

You will begin to notice performance suffering as the file size approaches 1 MB.  Most people find it unusable at some point between 1.5 and 1 MB.  Another rough estimate is that performance seriously suffers when there are ca. 1250 components (i.e. folders).

As the file grows you may wish to Split FACT files for editing.

Also, note that with larger files, FACT functions such as assigning folder numbers, etc., can take a very long time (over an hour) to complete.  XMetaL may appear as "Not Responding" in Windows, but simply allowing it to run will usually result in the process completing successfully.