This paper describes an in-depth case study conducted by Intel in conjunction with EYP Mission Critical Facilities (now an HP Company) and Emerson Network Power. The study compares the costs and benefits in selecting a 400 volt directcurrent (Vdc) design over the typical North American 480-208 volt alternating-current (Vac) design for a 5.5 megawatt (MW) data center. The study concluded that energy savings of approximately seven to eight-percent could be achieved over high efficiency, best practices 480-208 Vac&mdashwith a 15-percent electrical facility capital cost savings, as well as a 33-percent space savings, and 200-percent reliability improvement. The paper points out the differences in configuration between the 400 Vdc and 480-208 Vac designs. It also discusses what is required to enable widespread adoption of 400 Vdc designs.