The purpose of this paper is to quantify the sensitivity of the Global Precipitation Measurement (GPM) mission core observatory Dual-frequency Precipitation Radar (DPR) with focus on the Ka-band detectability of light rain and snow in comparison with the Ku-band capability. In this work, storm top height (STH) is utilized exclusively as the metric of radar sensitivity. The GPM DPR standard product level 2 version 3 is used in this analysis for the period from April to August 2014. The Ka high sensitivity (HS) mode and Ku have little systematic difference in STH over a broad range of the histogram, implying that the advantage of the Ka HS mode may not be as distinct as expected. The non-Rayleigh scattering effect may have partly offset the sensitivity advantage of the Ka HS over the Ku.