Power Consumption and Performance per Watt
Testing power consumption has become just as important and relevant in recent years as judging performance of these processors. And unfortunately, testing power consumption has also become a lot more complex than it used to be. Where as we used to just simply test and idle and a load configuration from the wall, new advancements in multiple-core processors, changes in how power planes are controlled on these CPUs and software complications give us a bit more to think about in our power testing.
Idle power consumption is definitely higher than Clarkdale and Lynnfield here (though part of that could be the motherboard/platform differences) but the Core i7-980X is still lower than the results on the Core i7-975 and other Bloomfield CPUs. Why? Likely because of the 32nm process technology and slight tweaks to power efficiency in the new core. Under a full load, keeping mind that this is 6 cores not 4 like Bloomfield, the Core i7-980X is using LESS power than the Core i7-975 and about the same amount as the Core i7-920 at stock settings. Pretty impressive.
Performance per Watt Measurements
Now I want to evaluate how the different processors tested here relate to each other in terms of performance per watt. To do this I took the load power consumption of each processor and divided it into the benchmark result to create a new metric like Hz/watt (for Euler3D) or FPS/watt for the games.
While I was impressed with the raw power consumption numbers of the Core i7-980X, the results in terms of power efficiency are even more impressive! Because the Core i7-980X uses less power than the Core i7-975 while performing noticeably better in many cases, it makes sense that effective result is a much more efficient CPU when you are utilizing all the available processing ability. The only outlier is in Far Cry 2 where the performance / watt is actually right on par with the other Core i7 LGA1366 processors.