FreeFileSync Forum

Were those slow jobs on that drive or also others? If your drive was about to fail slow speeds from it could be expected.

"Ignore" = "Continue anyway" as is easy to find out.

I'm using FFS to sync a folder between 2 macs through a gigabit Ethernet network, but somehow only getting transfer speeds up to about 25MB/s, that often can fall down to 10MB/s or less for several seconds. Copying the same files that would be synced manually from the Finder results in full ~100MB/s ...

It means you need to manually choose what to do for that file.