Copying between two drives - best speed?

[OspreyO]

If I'm coping/Syncing between two drives

A>B
B>A

I'm thinking you'd get best speed (the drives synced) writing to one drive first, then to the second so its one constant sustained write. Rather than having files copying both directions at the same time. The replicator too I use only schedules one copy at a time, there's no concurrent writes. If that makes sense.

 

[rpstewart]

Copying in both directions simultaneously is asking for trouble. However just because you're reading from one and writing to the other doesn't mean you'll get the best speeds the drives are capable of all the time. The disk heads will still have to jump between the actual data and the file tables all the time so the smaller the files being copied the slower the overall rate will be.

 

[OspreyO]

I've never had a problem with copying in both directions at the same time. Done it for years. But you do notice the transfer speeds up when there's only one going on at a time. Obvious I suppose.