Slow backup to external FW drive

[rhorer]

I'm on a PowerBook G4 1.5GHz with 1.25GB of RAM. When I back up one Firewire drive to another Firewire drive with SuperDuper using the 'erase then copy' method, my average copy rate (as reported by SuperDuper) is just under 4 MB/s. When I use 'rsync -aE' from a Terminal.app command line to make that same copy, my speed averages around 18 MB/s. Why might SuperDuper be so much slower?

[dnanian]

Because rsync -aE isn't actually preserving everything in the file, in most cases. I think you'll also find that subsequent Smart Updates with SuperDuper! are significantly faster.

I haven't found that rsync vs. SD!, in overall speed once done (time elapsed), is that different -- it's possible, too, that the measurements are not entirely comparable.