Companies could make significant savings in virtualising their datacentres if they had a better understanding of how their servers were being used. 

That's according to Berkshire-based software company Centrix which has launched its WorkSpace ROI calculator. The free tool has been designed to help businesses investing in virtualisation assess where further server, application and energy cost savings can be achieved.

According to Centrix's Laurent Séraphin, senior director of product management, companies know that virtualisation will reduce the number of servers they need but they need guidance as to which servers are being inefficient. "Without our tool, they're cutting blind," he said.

The free tool is just part of the Centrix offering. The free tool advises companies on the level of savings that could be made the company also offers users proof-of-concept software that will calculate exactly what servers can be withdrawn and greater detail about cost savings. "The calculator gives you a guidance on the savings that can be made, the proof-of-concept software gives much greater detail," said Séraphin. "For example," he said, "We know which applications are being used and not just installed. We know that when we survey an enterprises' PCs, that half the application not used - either because standard builds are bloated, or because an application had been used extensively a few years previously but was now no longer needed."

Séraphin said that the calculator would not only work out the savings that could be made by withdrawing servers but would also calculate the licensing costs that could be saved as well as the savings in power and cooling made by reducing the number of servers in a datacentre. "It's the reduction in the numbe of servers that is nearly always the bigger saving," he added.

As to the reliability of the tool, he said that so far the calculator had proved to be really accurate - with predictions well within 10 percent of the final figure. He added that the cost of the complete tool was £200 per user, or on a subscription model of £10 per user per month. He said that the use of the tool could show a return on investment between three to six months.