How to keep energy bills down

Analyst firm Gartner recently estimated that by 2008, 50 percent of current datacentres will have insufficient power and cooling capacity to meet the demands of high-density equipment such as blade servers and storage arrays.

And as power requirements continue to grow, rising energy prices, combined with government-imposed levies on carbon production, will inflate utility bills to the point where they represent the second highest operating cost in 70 percent of worldwide datacentre facilities by 2009, Gartner added.

To address this challenge, vendors have been busy redesigning their CPUs, power supplies, heat sinks, cooling solutions and power management systems to aid the delivery of more processing power while using less electricity.

Bernhard Brandwitte, director of product marketing for Fujitsu Siemens Computers, which conducts performance testing on different vendors’ servers and storage systems, knows better than most the challenges facing equipment manufacturers when it comes to designing energy-efficient products.

He points out that running servers in slightly hotter environments may save on power bills, but could cost more in the long run because components are more likely to fail in warmer temperatures.

“Heat affects the lifetime of components – there is a ratio between how warm you run something and how quickly it fades,” said Brandwitte.

The CPU currently accounts for around 35 percent of total server power consumption, but the electricity requirements for different types of RAM, cooling fans and PSUs must also be addressed.

And while the first challenge may be to reduce the amount of power each of these system components consumes, it is also necessary to extend the capabilities of servers so that optimal performance can be achieved with the minimum amount of physical hardware.

Brandwitte said firms should look at consolidating their servers by virtualisation, thereby optimising performance and reducing the number of physical machines.

Mike Walters, consulting systems engineer for NetApp, is tackling the energy issue from the storage angle. His firm is investigating ways to make its storage arrays more energy efficient. This includes hardware, by improving PSU and CPU electricity consumption, and software, by using de-duplication solutions to reduce the volume of data that has to be stored, and therefore the number of disks needed to accommodate it.

“Drives work best and are more resilient when they are kept spinning, so it is better to try to save energy by slowing them down rather than turning them off completely,” Walters said. “Sata disks help to [cut energy requirements] by shoehorning more data into a single array.”