Expectations on copy speed

[xochi]

My general experience on reasonably fast machines (doing backups to local internal or external firewire drives) is that I get average actual copy speeds in the range of 5-15MB/sec for a fresh backup (Erase, then copy), and can get effective speeds in the 50-150MB/sec range for Smart Updates when less than 10% of the drive needs to be copied.

It's clear that the Erase then Copy speed is slow -- it is clearly not disk-speed bound (since FW400 can do 40MB/sec). I believe that these speeds could be a lot faster if the comparison code were optimized. Whether this slowness is in Apple's OS or in SuperDuper's code is not clear...