As the diagram shows, Intel's 4.5 GHz Core i7-3770K beats the two competing platforms in our efficiency test, which consists of almost all the applications used in this article, by using the fewest Wh (watt-hours) of energy.
The Core i7-3770K's elapsed run time is the longest by just a hair, since the Sandy Bridge chip runs at higher clock rates and the Sandy Bridge-E processor boasts more cores. But Ivy Bridge’s clear win in the efficiency department outweighs its small performance disadvantage.
The verdict is in: under load, Ivy Bridge leads in performance per Wh. An overclocked Core i7-3770K is the new enthusiast-oriented efficiency champ.
The efficiency diagram documents our findings in visual form.