I'm not sure I understand, any file that isn't duplicated is unique, seems that would be a large scan for what is, essentially, a secondarily added tool.
For example: there is a backup on different media created by simply copying from the primary disk. You need to understand how they differ? What files were added or removed in a later version. That is, from the whole set of files to compare sets subtract the duplicates.
Например: есть резервные копии на разных носителях, созданные простым копированием с основного диска. Нужно понять, чем они отличаются? Какие файлы были добавлены или удалены в более поздней версии. То есть, из всего набора файлов в сравниваемых наборах вычесть дубликаты.
Are you trying to compare the contents of two folders to see what files are different by date, size, missing, etc?
If so, there are a number of utilities available for that purpose. I have used Synchronize It, by Grigsoft, for years and have found it to be very helpful.
Regards,
JB