Recent mobile devices such as smartphones can provide diverse functions by supporting various kinds of applications. To maximize the efficiency of mobile devices, power consumption should be considered since it has strong relation with battery life. This paper measures and analyzes the power consumption of smart devices varying critical configuration components such as processor type, display device and operating system. Additionally, various kinds of applications are executed to consider diverse aspects of characteristics of different applications. As we predicted, increasing processor complexity and display size results in more power consumption. Compared to idle case, Android consumes more power by 161% on average whereas iOS consumes more power by 142% on average. Therefore, we can know that the iOS power efficiency is better than Android by 19.7% on the average. This is because hardware/software optimization in iOS is better than Android.