ITU-T L.1318 PDF

This Recommendation defines the integrated circuit metric for energy efficiency (TIME) as the Q factor (also known as "quality factor" or "Q"). Q factor provides a key means to accurately express energy efficiency at the integrated circuit (IC) level.

This Recommendation defines Q factor as a metric for IC energy efficiency;

This Recommendation is applicable to all ICs and differentiates ICs with Q ≥ 1000 (highly energy efficient) from those ICs with Q = 1 (current ICs).