Dell has announced a new range of more energy-efficient PowerEdge servers.

The Energy Smart models 1950 and 2950 offer a 25 percent improvement in performance per watt compared to the standard 1950 and 2950, Dell claimed. The announcement follows Dell's September launch of Energy Smart OptiPlex business desktop computers.

The Energy Smart server features include a processor that draws only 40 watts of power versus the 65 watts or 80 watts in standard servers. Energy Smart servers will also offer only 2.5in disk drives, smaller than the typical 3.5in drives.

Those design changes may diminish performance in a way some customers would find unacceptable, said Jay Parker, director of PowerEdge Servers in the Dell Product Group. But for others, the goal is energy efficiency. "We would expect somewhere in the 10 to 20 percent range of our customers to be interested in this product and to ultimately migrate to this. But there is a whole other set of customers who need more configurability or [for whom] power efficiency is not a priority," Parker said.

The Energy Smart servers also feature redesigned power supplies and cooling fans, as well as software that regulates the processors and memory to power the server up and down as computing demand changes.

Vendors of servers, desktops and other enterprise hardware are on an energy-saving kick these days, addressing the need to cut data-centre power consumption. The lifetime operating cost of powering servers and cooling them with air conditioning is becoming more of a concern to data centre managers than the price of the server itself.

HP last week announced what it calls "Dynamic Smart Cooling" for data centres. Heat sensors on server racks send signals to a control panel that adjusts the air-conditioning output. HP's technology doesn't address the energy problem as directly as Dell does by making the server energy-efficient, Parker said.

"You have to optimise the server, because ultimately that has a huge ripple effect on the other infrastructure pieces in the data centre. In our mind [HP's technology] seems to ignore the first obvious step, which is to address the server itself," he said.

Pricing for the Energy Smart 1950 starts at $2,449, $100 more than the standard 1950. Pricing for the Energy Smart 2950 starts at $2,619.