Data centre infrastructure provider Emerson Network Power is part of a group that has produced a universal measurement of power usage effectiveness, termed CUPS (compute unit per second). “Until now we have measured the power going in to a data centre and how much got to the IT equipment,” explains Emerson’s Director of Marketing, Peter Spiteri. Now CUPS can measure the amount of “useful work” that power is doing, giving a true idea of its effectiveness. So far the CUPS metric has uncovered one important fact: while data centre energy consumption has risen in recent years, the increases have been accompanied by dramatic gains in output and efficiency. Spiteri suggests this could have implications for the rate of equipment refreshes in the future, as it will be more financially advantageous to replace servers rather than run older ones at lower efficiencies.Data centre professionals can experiment with CUPS relative to their own data centre in an online efficiency calculator available at www.efficientdatacenters.com.The CUPS unit of measurement is being put forward in the white paper Energy Logic: Calculating and Prioritizing Your Data Center IT Efficiency Actions, which is currently up for ratification with The Green Grid. This is a follow-up white paper to the Energy Logic paper published after the worldwide Energy Logic Symposium held last year (for more information, visit http://tiny.cc/tGjGh).