In a past Mission-Log, we've reviewed the power consumption of so labeled “green” Switches (consumer-grade/unmanaged) that could be used in off-grid environments and they performed really well. Compliant with IEEE 802.3az Energy Efficient Ethernet, these switches consume less energy by cutting down on power consumption when the traffic volume is low and automatically measure the length of the connected cables to adjust power usage if cable connections are shorter than 20 meters. In addition, they monitor link status of every port and drastically reduce power consumption when a port is without a link.

With more technology and infrastructure, the need increased for more Ethernet features like VLANs, trunks and many other features, usually only offered by expensive, loud and very power hungry managed/enterprise switches. Luckily this has changed and we could test and already deploy managed but very low power and fanless (silent) switches: Check out the D-Link DGS-1100-8

For better comparison all measurement results have been put together:

		DGS-1008D G2		DGS-1008D G3		DGS-1100-8 Rev A1
Clients	Mode	Current	Power	Current	Power	Current	Power	Wall
0	Switch only	66-93mA	0.33-0.46W	67-111mA	0.33-0.55W	105mA		0.8W
1	Client Stdby	100-160mA	0.5-0.8W	109-124mA	0.54-0.62W	131mA		1W
2	Client Stdby	141-194mA	0.70-0.97W	153-161mA	0.76-0.80W	154mA		1.1W
2	Client Idle	160-200mA	0.8-1W	170mA	0.85W	212mA		1.5W
3	Client SCP	250mA	1.25W	210-220mA	1.07W	238mA		1.7W
4	Client SCP	250mA	1.25W	210-220mA	1.07W	264mA		1.9W

The DGS-1008D test candidate has been up and running 24×7 for more than 365 days now without any glitch or the necessity to power cycle. Power saving often leads to compromises in performance but the switch performed equally well compared to a CISCO 3560, that was in use before power consumption became a major issue.

Grid powered devices still have the luxury to be able to consume more power than absolutely necessary, since the limiting factor is money and not power itself. Off-Grid scenarios change that point of view on costs, as the value is no longer money, but the painfully finite element of power itself.

There are still a lot of devices out there with a standby-consumption of well above 10W, the DGS-1008D G3 connects 4 clients, actively transfers a lot of data and consumes about 1W. D-link obviously did a good job with this, although there is a little curiosity in StandBy: The G2 consumes a little less power in StandBy, when no clients are connected but the G3 saves considerably more power when active so overall the G3 is a very good evolutionary step in low-power consumption Gigabit-Ethernet technology.

The only drawback of these switches is their un-managed nature. Hopefully, in the future even managed switches can operate with this kind of power consumption profile.

Other manufacturers, who also build similar products, may always send us their products for hardcore real live evaluation as well :)