Energy Consumption Under Heavy Load
At 100% utilization for all CPU cores, the differences between the 65 and 45 nm technologies become powerfully obvious. For this test, we measured the power consumption directly from the 12 volt rail that supplied the CPU.
CPU Power Consumption at 100% Load
Whereas the Phenom at 2.6 GHz requires up to 139 watts, the 2.8 GHz Phenom II requires only 88 watts. At 3.0 GHz, the Phenom II X4 940 is also significantly lower at 93 watts. But the Core i7 is outside the Phenom II’s reach at 74 Watts, and the Core i7 965 Extreme consumes only three more watts (94.9). The Core 2 Quad Q6600 comes in 5 watts under the Phenom II (at just under 83 watts).
System-Level Power Consumption At 100% Load
The Core i7 chipset requires a lot of power, while a Phenom II system consumes less power even when the more power-hungry CPU is factored in. AMD’s power consumption is about on par with a Core 2 Quad Q6600 system, and noticeably lower than that of a Core i7 platform system. When it comes to overall energy consumption, AMD makes a much better showing thanks to its more energy efficient chipsets.