No, Ethernet consumes relatively low power to operate.
No, Ethernet consumes relatively low power to operate.
I recently changed my internet speed from 1.5 to 20 Mbps down. Because I reside in an area with unreliable power, I also purchased an APC UPS with a built-in watt meter. When I connect only Wi-Fi, the displayed power is zero watts, which seems unusually low—there’s no decimal point on the screen. However, when I connect via Ethernet, it shows around 5 watts. I’m curious why this difference is so significant. It appears to be a standard-looking box provided by the ISP, just a typical container for Gigabit Ethernet using a Cat 5e cable.
I assess Ethernet performance by isolating the connection and measuring throughput, latency, and packet loss. For Wi-Fi, I evaluate signal strength, bandwidth utilization, and stability under various conditions.
The router connects to the UPS and displays its power consumption, Wi-Fi remains active constantly, while Ethernet cables are absent from the router. On the UPS screen, power reads 0 watts when Ethernet is off and 5 watts when it is connected. The router appears as the sole device in the UPS and only shows whole numbers.
The setup varies significantly, like a Raspberry Pi zero consuming just half a watt when idle and a full watt when the CPU and Wi-Fi are active. The Ethernet port, however, uses extra power through constant LED lighting, even when disconnected. This doesn’t mean you can boost Wi-Fi power, but typical routers do manage energy savings. Buying a network switch has freed up more RJ-45 ports and reduced heat buildup.
I just ran another test and it showed 0 watts in both modes—WiFi alone and WiFi plus Ethernet—so maybe the ups reading isn't very precise.
I understand my setup definitely isn't it. It behaves similarly by either showing zero or instantly jumping to 16W. It displays zero even when the PC is in standby (probably around half a watt) and with two consoles on, which usually don’t idle low. This suggests it can’t accurately measure loads below a certain threshold. It’s odd because a standard watt meter can read down to about 1W, so you’d expect a UPS to be more precise.
Both devices use minimal energy. The router’s wireless module likely draws less than two watts. Without any Ethernet cables connected, the built-in network switch might shut down to conserve power. Once a cable is attached, both components operate normally. Ethernet connections also shouldn’t exceed a few watts. On the computer side, the network card consumes under one watt—modern chips are energy efficient, cutting transmission power to save milliwatts. Overall, your system uses at least fifty watts, making the router’s five-watt output negligible.