Abstract-To the best of our knowledge, there have been no efforts in devising power consumption prediction models for an idle server, where this latter contributes approximately 66% of the maximum power drain. In this paper, we propose power consumption prediction models for idle servers by taking into account their constituent components such as processor, memory, hard disk, fan and power supply unit. To this end, we identify the relevant energy-related attributes of each component necessary for the idle power consumption predictions. Furthermore, based on the proposed models, we provide an in-depth analysis by considering several types of servers (e.g. rackable, blade, etc) having different hardware characteristics and energy-aware mechanisms