Dell Inc. (Dell) commissioned its System Performance Analysis team to compare similar 4-socket servers, the Dell PowerEdge R815 and the HP ProLiant DL585 G7, using the industry-standard SPECpower_ssj2008 benchmark to compare the performance, power draw and performance/watt using the latest AMD Opteron™ 6000 series processors. First, the servers were compared in an apples-to-apples manner, configured as similarly as possible with four 12-core AMD Opteron Model 6176 processors, and identical memory and hard drive selections. Then, differences between the platforms were examined by changing one parameter at a time and remeasuring power efficiency. To ensure the lowest power draw, the HP ProLiant DL585 G7 was equipped with its more expensive High Efficiency power supplies for all tests.