Placing data center power and data cables in overhead cable trays instead of under raised floors can result in an energy savings of 24%. Raised floors filled with cabling and other obstructions make it difficult to supply cold air to racks. The raised floor cable cutouts necessary to provide cable access to racks and PDUs result in a cold air leakage of 35%. The cable blockage and air leakage problems lead to the need for increased fan power, oversized cooling units, increased pump power, and lower cooling set points. This paper highlights these issues, and quantifies the energy impact.