Phenom processors manufactured with 65nm process have never been energy-efficient. They looked even less attractive from this standpoint than quad-core Intel processors based on 65nm cores. Now AMD suggests that we should compare the same core of the old Phenom processors in its triple-core implementation against contemporary 45nm Intel CPUs based on dual-core semiconductor dies. I doubt that anything good may come out of it and the outcome of Athlon X2 and Pentium power consumption comparison is evidently predetermined. Nevertheless, we have to check out the numbers in order to estimate the disaster.
The numbers below show the total power consumption of the tested platforms (without the monitor). During our tests we used 64-bit LinX 0.5.8 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, Cool'n'Quiet and Enhanced Intel SpeedStep.
All processor power-saving technologies get activated in idle mode therefore the power consumption of our test systems doesn’t differ too much. Nevertheless, the advantage of CPUs manufactured using more advanced technological process is evident even in this case.
Things get much worse as the load increases. AMD CPUs can’t compete against Pentium in performance-per-watt – it is for a good reason that these processors are often used in HTPC systems. Athlon X2 on a 65nm core is considerably far behind the Intel offerings, therefore, if you do care about the power consumption and heat dissipation of your system, then forget about dual-core AMD processors for good.