Ingest your disk collection, so diskm8 can report on them:
diskm8 -ingest C:\Users\myname\LotsOfDisks
Find Whole Disk duplicates:
diskm8 -whole-dupes
Find Active Sectors duplicates (inactive sectors can be different):
diskm8 -as-dupes
Find Duplicate files across disks:
diskm8 -file-dupes
Find Active Sector duplicates but only under a folder:
diskm8 -as-dupes -select "C:\Users\myname\LotsOfDisks\Operating Systems"