Is PoE more efficient than plugging in adapters for each network device?
And at what scale does it start to matter?
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From my perspective; I’m going for a 3 node mesh router, plus 2 switches, and was considering if in 5 years time the electricity difference would be less than the extra upfront cost. The absolute max length of cable would probably be around 30m
Depends on the voltage.
Most IT devices’ key components run at 3-5 V nowadays and the voltage needs to be converted down if the PoE voltage is higher. This introduces losses, especially if a linear regulator is used as opposed to a buck converter. On the other hand, one powerful PSU is slightly more efficient than a lot of smaller ones.
I don’t think there is a huge difference. If you run a lot of tiny devices (too small/cheap to use a buck converter) off a significantly higher voltage like 24 V or 48 V and/or the cabling is very long, PoE will be less efficient. If the PoE voltage matches the devices’ adapters’ voltage and the cables are reasonably short (<30 m) with few connectors, PoE may be more efficient.