Power density spectra at three different energy bands 3.0–8.0 keV (first column), 8.0–20.0 keV (second column), and 20.0–80.0 keV (third column) are shown for three observations when strong QPOs are detected at ∼2.55 Hz (top row), ∼4.53 Hz (middle row), and ∼6.55 Hz (bottom row) respectively. Due to observed break in noise continuum, the broken power-law model is used to fit the noise component, while Lorentzians are used to fit QPO and harmonic features. It may be noted that a significant, excess noise component (modeled with broad Lorentzian) appears in the PDS with higher QPO frequencies at the energy ﹩\gt 8.0\,\mathrm{keV}﹩. Such features were not detected by RXTE due to its highly reduced efficiency in 8.0–20.0 keV energy band.