National Semiconductor has published the metrics behind its 'PowerWise' brand of energy efficient chips, allowing engineers to judge its claims against other manufacturers.
"National has strict criteria for power and performance and is setting a standard where none currently exists," said National. "Depending on the type of IC, National used product-specific, practical formulas incorporating 
commonly used engineering measurements to determine each efficiency specification."
For example, the metric for a high-speed data converter factors in both dynamic performance and the power consumed.