The controls on this options page control how folder comparisons are performed.
File timestamps and sizes only
Check this option to compare only file sizes and last-modified timestamps when determining whether a file has changed. The number of changes between changed files is not calculated, so the Changes column will show ≥1 rather than a complete count for changed files.
File content when timestamps or sizes are different
Check this option to have Merge always perform a thorough comparison between files to determine whether they have changed if the file sizes and/or last-modified timestamps are different. The Changes column will show the number of changes between the files.
File content (using file comparison rules)
Check this option to have Merge always perform a thorough comparison between files to determine whether they have changed. The Changes column will show the number of changes between the files, and Comparison Statistics and folder comparison reports will contain more detailed information than if only timestamps and file sizes are compared.
Compare byte-by-byte for files larger than # KB
When performing a thorough comparison between folder hierarchies, the Merge comparison engine may take a long time and use a large amount of memory when it encounters large binary files.
Check this option to make Merge perform more memory-efficient comparisons between files that exceed the size specified in the adjacent entry field. This option only has an effect when thorough comparisons have been enabled. Note that the algorithm used for byte-by-byte comparisons treats all differences between files as significant; it will not ignore differences in whitespace and line endings, even if you have those options turned on for normal comparisons.
For large files, this type of comparison is typically faster and uses considerably less memory than using the default comparison engine.
The Changes column in the folder comparison window will display ≥1 or 0 for byte-by-byte file comparisons depending on whether the files have changed or not.
Treat timestamps as identical if they differ by less than # ms
Use this control to adjust the margin of error allowed by Merge when checking that two timestamps are the same. When comparing files across a network or on different file systems, timestamps can sometimes differ by a small amount.
This option only has an effect when thorough comparisons are turned off (that is, when the File content (using file comparison rules) option has not been selected).
Ignore time-zone differences (see Help)
Different time-zones used by the file systems that contain your files and folders can sometimes cause timestamps to appear to differ by one or more hours. By checking this option, Merge will ignore hour-sized differences (up to a maximum of 13 hours) when comparing timestamps. The adjacent Treat timestamps as identical if they differ by less than # ms option will, if checked, be taken into account as well when comparing timestamps.
This option only has an effect when thorough comparisons are turned off (that is, when the File content (using file comparison rules) option has not been selected).