As the title states, I'd like to know if I'm consuming more power when connecting to the internet via wireless (assume 802.11n, if it matters) or if connected through an Ethernet cable (with wireless turned off).

 

Are you looking for total power or just from the end user device perspective? IE. from a "laptops" point of view?

Most devices allow you to power down both devices, so once you pick which one uses less power, you need to remember to turn off the other device.

I would think a simple multi-meter test would show you? You'd want to tax the network connection during the test. Perhaps download a large 5GB file or something during your metering.

 

I guess I am looking for the power relative to the laptop, as I'm sure the laptop's power consumption is listed somewhere in the user manual.

 

No straight answer.

Gut feeling is that a wired network connection running at 100MB would be less power than a wireless network.
However, the higher the frequency, the more power required. So Gigabit would/should take more than 100Mb, given the same distance and quality of cable.

The same applies to wireless. The power used depends upon the quality of the connection. If there is interference, then there needs to be retransmission in order to recover bad data sent.
Also, the power used to send depends (should) upon a quality factor determined by the receiver. It the quality drops, then the power must be increased. Consider on your mobile, if it has 1 bar of signal, the battery drops faster than if it has 4 bars, the same occurs with wireless on computers.

 

it depends i would think because on my laptop you can set them to disable eachother based on what is in use. the wireless has some adjustments in MW(miliwatts) of the transmiter in the laptop. i would guess that there about equal. wifi may be slightly more because of the transmiter as well as the diferent senceing protocals used in wifi comunications. but it would seem to me that they woauld be very close with in a couple % of eachother. also consider the resistance of the coper medium used the longer the cable the more resistance. based on ohms law this should mean it would use more power to send the signal over the greater resistance.