Independent testing has shown that companies rolling out D-Link's Green Ethernet switches can reduce operating expenses, even when the switch is fully saturated with network traffic.

The testing was conducted at Ixia Labs' EMEA site in Marlow by independent network kit testing outfit Broadband-Testing.

A subsequent report filed by Broadband-Testing labs director Steve Broadhead shows conclusively that D-Link's claims for its DGS-1224T 24-port Green Ethernet Gigabit Smart Switch have been validated by the tests.

"With default gigabit mode enabled, and with a 100 per cent network traffic load, the Green Ethernet switch consumed 47 per cent of the power used by D-Link's own DGS-3627 24-port switch," he said.

Broadhead compared D-Link's Green Ethernet switch with its DGS-3627 24-port switch and a D-Link DGS-3426P 24-port Power-over-Ethernet switch. The test used Ixia's XM12 test hardware and its new IxGreen software application, allowing network load testing data and power consumption readings taken from a hardware multi-meter to be compared.

At zero per cent and 50 per cent network traffic load, the DGS-1224T Green Ethernet switch consumed 64.1 per cent and 53.7 per cent respectively of the power used by D-Link's DGS 3627 switch.

One method by which D-Link's hardware reduces power consumption is that its switch places the port to which the device is connected on less power-consuming standby mode when a connected device is turned off. D-Link's switches can also adjust power output according to network cabling distances.

D-Link's Green Ethernet switch offers an opportunity to significantly reduce power costs for firms using switches close to their full network capacity.

However, one of the current problems with testing switch power consumption is the lack of a global standard for running such tests, which means that useful comparisons between competing network kit could be undermined by claims of " non-standard testing".

Ixia system engineer James Ramsay said that datacentres are under significant pressure to reduce cooling problems, and that the industry needs a global energy efficiency metric covering Europe and the US.

Nigel Moulton, European enterprise and SME vice president at D-Link, said that all D-Link switching products would be moved to similar 'green' hardware configurations over the next six to nine months, and that its wireless LAN systems and network attached storage hardware would be "similarly specified".

Moulton added that there are macroeconomic considerations, but that CIOs could justifiably offer green network hardware to network IT managers as a " serious consideration".