For bulk transfer, the absolute fastest I've seen is piping tar through netcat and doing the reverse on the receiving end - on a 10-gigabit lan that results in

For bulk transfer, the absolute fastest I've seen is piping tar through netcat and doing the reverse on the receiving end - on a 10-gigabit lan that results in transfer at the hdd speed. That was between my personal machines with consumer-grade SATA hard disks. The situation probably changes once you add hops and have multiple disks to read from at once.