The performance score we need in order to calculate efficiency comes from the total run time to complete our efficiency workload.
Here's the meat. Our analysis of effective application performance per watt results in a serious advantage for the new six-core processor. The Core i7-980X gets things done faster and requires less power, resulting in much improved efficiency.
This efficiency diagram shows power consumption at every point of the benchmark run and the time required to complete the workload. Clearly, the new processor requires considerably less power (red line) than the Core i7-975 quad-core. You can see that there are threaded workloads (high spikes and plateaus) and applications that are less optimized (lower power levels).