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.
Intel listed the TDP of the Core i3-530 to be identical to that of the other Clarkdale processors and that appears to be the case here. The slowest offering uses about 10 watts less power than the Core i5-661.
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.
The general rule here is basically this: the Core i3-530 performs at level below the Core i5-661 and yet is only using 10 watts less power than the higher speed CPU to do it. It makes sense then that the performance / watt of the Core i3-530 would fall just behind the Core i5 Clarkdale part we tested first in January.