To get a good look at your System config. for conflicts or issues, you can run this utility http://etrecheck.com
If you need help interpreting the report you can post it here in its entirety in the "Additional Text" box in the editing toolbar below, in your reply.
You can set its preference to "Allow full Disk Access", with this you get a digest of issues from the last 7 days that are saved in your system.
A properly functioning drive should complete in ~ 3 minutes. Marginal blocks that must be re-read multiple times in order to get good data will add extra run-time.