Abstract: An apparatus for directly measuring performance offset of NFET transistors with respect to PFET transistors in CMOS device processing includes a ring oscillator whose frequency is used to measure random across chip variations, as well as correlated across chip variations; a balanced inverter having a input driven by the ring oscillator, wherein the balanced inverter is designed to be formed such that a current drive capability of one or more NFET devices of the inverter is substantially equal to a current drive capability of one or more PFET devices of the inverter at a given operating temperature; and a capacitor coupled to an output of the inverter, with a voltage across the capacitor indicative of whether a skew exists between NFET device performance and PFET device performance.