Formally, the increased number of processor cores in the new Phenom II X6 CPUs didn’t affect the TDP value. Just like by other top Phenom II processors, their TDP is set at 125 W. This results from certain improvements in the utilized production process, as well as from the introduction of the new processor stepping. Moreover, do not disregard lower core voltage compared with that of quad-core Phenom II X4 CPUs, which is specified at 1.4 V.
However, it is hard to believe that 1.5 times increase in semiconductor die complexity didn’t affect the power consumption. Therefore, in order to get a more detailed picture we performed some power consumption tests. The graphs below show total system power consumption (without the monitor) measured “past” the power supply unit and representing overall power consumption of all system components. In this case we do not take into account the efficiency of the PSU itself. During our tests we used 64-bit LinX 0.6.3 utility to load the systems to the utmost extent. Moreover, to ensure that we estimate the power consumption in idle mode correctly we activated all power-saving technologies, such as C1E, AMD Cool'nQuiet 3.0 and Enhanced Intel SpeedStep.
In idle mode Phenom II X6 based Socket AM3 system consumes just a little more power than a similar system with Phenom II X4 965.
We see the same exact picture under heavy load. As promised, the power consumption of the new six-core AMD processors is not very much different from that of the top Phenom II X4 CPU. And it means that Phenom II X6 based platforms boast higher energy-efficiency than their predecessors as well as LGA1366 systems. However, LGA1156 platforms still outperform them in this respect.