We demonstrate, for the first time, modulation of power-performance of a ring oscillator fabricated on thin-BOX (buried oxide) FD (fully-depleted) SOI using independent backgate controls for nFET and pFET. The thin BOX facilities an effective modulation of ring characteristics with small (1-2V) independent backgate voltages. Leakage current per stage can be reduced by more than 100x with 30% increase of inverter delay. In addition the inverter delay can be improved by 15% with 2x increase of the stand-by current. Compatible with conventional CMOS process, our results suggest the backgate technology, an additional knob for power/performance optimization and variability control, is attractive for continued CMOS scaling.