I've got this problem where when I copy large files (2-3GB) from the large HFS+ partition on my USB drive to the small FAT32 partition on the same drive, my system lags really badly. I don't mean just ...
If you cannot move or copy large-size folders from one external HHD to another external HDD, then this post will help resolve the problem. Moving a large size file or a huge folder is not uncommon.