It's a pressing problem; how can data centers be made more energy efficient when managers often have little idea as to the true environmental cost of running their data centers.

A British company claims to have the answer. Consultancy Migration Solutions has introduced an audit that can assess all the energy consumed within a data center. According to Alex Rabbetts, managing director of Migration Solutions, businesses should look beyond industry benchmarks such as PUE and DCiE "We already have a bunch of industry metrics but they provide only a small part of the answer. For example, if you took readings in summer and winter, you'd get two different sets of figures, all you're getting with them is a snapshot at a particular time."

He said that the Migration Solutions' Environmental Report and Audit (ERA) took into account a wide variety of other factors. "It's not just about power, you have to take a holistic approach to measuring IT efficiency. We look at factors such building construction, windows, cooling for example as well as power."

While much of the debate on data center optimization has focused on factors such as virtualization, Rabbetts said that this wasn't enough. "You can't run virtualization on x88 servers but if you take the old servers away, the energy efficiencies in disposing of them might well outweigh the advantages of upgrading the servers."

But he added that there were other factors to consider that the cruder metrics just wouldn't look at. "If you have a switch you need to look at whether it draws air up and down or from side to side, that has an effect on the way that you build a data center.

The Migration Solutions' audit costs around £2.500 and considers about 150 variables. Rabbetts said that it was difficult to say what sort of savings an audited firm could expect to make. "One thing that I would guarantee is that we would make some sort of power saving but it's hard to put a figure on it. It's fair to say that most of our customers are interested in saving money rather than looking to save energy - although that's a by-product."

When pressed to give a figure, Rabbetts said that a company could save something between 5 and 20 percent on power costs.

The company has just launched the audit to customers but has already signed up a number of trial lists, drawn, said Rabbetts, from a wide variety of industries.

Although the company is marketing the audit as an industry standard, there is no standard that the audit conforms to. "It's an interesting point," admitted Rabbetts, " tell me which body would ratify it."