I back up my laptop nightly to an external USB hard disk. When this disk directly connected to the laptop, a CarbonCopyCloner incremental backup takes about 5 minutes.  

But unplugging the disk is a minor impediment when I’m in a hurry to get to work, so the disk is now connected to one of our TimeCapsules. The same backups now take over two hours! Why? The laptop is connected to a gigabit ethernet switch, as is the TimeCapsule. Gigabit ethernet should be faster than USB2. I guess the bottleneck might be the laptop’s USB to ethernet adaptor, but that’s supposed to be gigabit too.

It’s not a problem – this backup runs at 23:30. (The laptop is also backed up via CrashPlan and TimeMachine, so I’m not worried that CCC is a snapshot rather than a father-grandfather-greatgrandfather-greatgreatgrandfather,… backup.)

Answers on the usual deep-fried tofu, please.