I am looking around for power-efficient network switches for my house and not finding any resources. Ideas? A simple 5-port would be fine although 8 would be better.

Could you give more specifics about what you are looking for?

If the goal is overall energy or resource efficiency, then using a second-hand switch would probably be the most efficient. (Taking into account the environmental cost of manufacture, shipping, recycling, disposing of, etc.)
There are tons of switches already built - so extending useful life
of a reasonable switch is probably more efficient than creating something new.

If need lowest power draw (e.g. to run off grid), then obviously
avoid more power hungry features like routers and wireless
(unless you need them).

This article
http://www.treehugger.com/files/2007/03 ... m_ener.php
has a link to a database of power usage of some devices,
can't remember if it covers things like net switches, and the database seems to be down at the moment.

You might also check some of the information about power over ethernet
on some of the networking sites. (Might help you find switches that don't take lots of power - although you would still have the question of how efficient the switch's power supply was.)

There have been some threads on SPCR about switching vs. non-switching power bricks, which might help there. Or if you have a computer that will be on whenever the switch is needed, you could run the switch with power from the computer. That would mean the switch was off when not needed, and, assuming the computer has a high efficiency supply, it might use less energy than a separate power brick. It also would not entail the energy of creating yet another power supply (to replace an in-efficient power brick).

Haven't seen many people testing power draw from switches, mainly because they typically don't draw that much (around 10w or so would be normal, I guess).

It wasn't mentioned whether you want 100Mbps or 1Gbps. There is a noticeable power draw difference between the two. Even running 1Gbps equipment at 100Mbps if you don't need the speed will save a watt or two at the NIC and at the switch.

A 100Mbps switch will generally draw less power than a 1Gbps switch.

I would pay attention to the type of AC power adapter the switch is shipped with, some are now shipping with a small, light AC adapter which will be more efficient than your typical wall-wart and if you happen to have the switch off draw a lot less power. For example, I recently bought a Linksys WRT-54GL and it came with one, but the older ones come with a heavy brick.

Right - switching PSes vs ones built around transformers and rectifiers.
Another thought - if the gear is near a PC you have on anyway (like a file server in the basement) and the router/firewall/whatever takes 5VDC or 12VDC you can power it with your PC power supply (an 80+ PC ps is going to be more efficient than a wall-wart switching ps). I haven't gotten around to doing this with any of my firewalls/routers, but do do this with all my backup drives...

Repost from another thread:

http://www.dlink.com/corporate/environm ... -ethernet/

I'm also wondering if i have a pc that's always on and acts as a file/printer server, if i make it into a router/dsl modem/firewall/internet gateway with a 4 port internal card + wireless card would save on electricity as much as it would save on space? It's just that a 4 port ethernet switch is so rare these days. I found one PCI 4 port 100Mbit/s for maybe 30$ and a PCIe 4x 4port gigabit for 500$ (!).

How much power does the 4 port network card take?

How much power does the computer take?

How active is the file/print server?
(i.e. can it sleep or hibernate most of the time, or is it on/actively serving stuff most of the time.)
Do you have the server set up to hibernate or turn off when not in use?

My guess would be that a dedicated 4 port switch would take less power than using a regular computer as a switch. But you may have more flexibility in getting a computer to turn off when not in use. So if the network has long periods of inactivity, might be able to cut the overall usage using the computer.

If main goal is compact space - can you find a space inside the PC case to mount a 4-5 port switch? (e.g. in a drive bay or near a back slot/vent).
The linksys 5 port switch sitting on my desk would easily fit into a 5.25" disk bay. (Would make it easier to adopt the suggestion about using the PCs power supply to power the switch too.)

The internal card shouldn't consume any more than the external box, and since it draws power from your PC's power supply, it just raises that efficiency. But for me, since i already have an external router it would create more ewaste to switch to internal now. I just felt like making it happen just for the fun of building that.
But I guess you're right.
For one thing my household (me and two homies) doesn't have enough critical mass to be running a computer always on. But back at my parents' house, my two brothers are downloading 24/7 so they could actually make use of a the headroom in the server pc. If it's a via system running at max 50w, and can go to sleep when not in use then it's not so bad, and saves a bunch of wire clustering.