Power supply without load: 0W
PSU plugged into Switch: 0.7W
3 computers infected with LAN cable: 0.9W
Data between 2 computers over the network duplex hunted: 1W
More must not say so. However, the values only apply to the 5-port switch. The 8 Port Switch can even take a bit more power.
An older 3Com Gigabit Switch 8Port for comparison:
Power supply without load: 0.5W
PSU plugged into Switch: 3,7W
3 computers infected with LAN cable: 5.0W
Data between 2 computers over the network duplex hunted: 5,1W