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Please note: I am not asking for specific product reccomendations.

I am in the process of expanding wired ethernet cabling in a building during a remodel. I currently have about 20 runs of CAT6a to various rooms and plan on another 16 to 20 more runs as more of the structure is remodeled. The actual ports will likely be heavily under-utilized, only 10-20% of these network runs will typically be in-use at any given time. Nevertheless, I still plan on installing many runs for future proofing and to avoid needing small 5 or 8 port switches in rooms.

These runs of cables will terminate at a central location in the basement, and will be connected to 1 or 2 network switches with all runs being connected.

My understanding of 802.3az from reading wikipedia is that the switch is able to turn off ports that are not active and thus save electricity. Since I will have a low utilization of connected ports, on the surface, this seems like it would be a big deal.

What I would like to know is if a switch supporting the IEEE 802.3az / Energy Efficient Ethernet standard would be worth the extra cost (over a less efficient switch) for this scenario. I imagine as technology progresses, all switches will support energy efficient features, but currently for those who are budget constrained, an older model switch is significantly cheaper than newer "green" switches.

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A copper ethernet link without an established link (at least one end disconneccted) uses near-zero power on any switch, even old ones. There simply isn't a complete circuit to transmit energy.

On standard switches, if a 10/100/1000-based-T copper link is up, it basically runs at full power even if no data is being transmitted because of differential signaling.

So EEE only applies to "connected but idle" links I believe, which is a pretty narrow use case, as in general a modern workstation is always doing something on the network in the background. So EEE may be helpful for connected workstations that have gone to sleep overnight but have Wake-on-LAN or similar functionality keeping the link up, but that's about it.

In short: don't worry about it at all, it should be the last feature you consider in a decision.

rmalayter
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