D-Link has announced the introduction of two first-to-market business-class unmanaged Green Ethernet switches. Developed to enable small to medium-sized enterprises to reduce their energy costs and optimise energy efficiency, the new DGS-1016D 16-port and the DGS-1024D 24-port high performance Gigabit switches claim to deliver energy savings of up to 45 per cent when powered down.

According to the company, the new switches don’t require any changes to existing network infrastructure and should not show any difference in performance over other switches. While it is too early to be certain, D-Link believes that reduced heat and power output should lead to greater longevity. The real question however is what impact will Green Ethernet have on consumption. The company says:

In early 2007, IEEE formed an Energy Efficient Ethernet (EEE) study group investigate this idea of power saving with network equipments when PCs and laptops (most of which ship with GigE cards now) LAN links are idle, or not utilizing full bandwidth. Researchers have estimated that in the U.S. alone, companies could collectively save $450 million a year in power costs by using such a technology.

Those savings may be ambitious and at the top of the range because according to Green Ethernet:

The following are some typical values estimated for US energy savings from EEE:

• 1 Gb/s link EEE: $250 to 300 million per year
• 10 Gb/s link EEE: $40 to 80 million per year

See this document for the detail.

In a SOHO environment, actual savings will depend on the cable length used. At present the optimum length is 20 metres.

This is one of the first announcements in what I see as a general trend towards managing power use in computing infrastructures. It is not an easy task because there are numerous complexities and interweaving factors that dictate exact power usage. In the scheme of things, the savings outlined are a flea bite when compared to total power usage. But at least it is a welcome start.