System Idle/Max Power Consumption
Let's first look at the idle and maximum system power requirements.
The AMD platform clearly requires more power when idle (102 W vs. 87 W equals 17% more) and the power requirement difference is even larger when under load, at 210 W vs. 163.5 W, or a 28% difference. Remember that the results cover all other system components, which also includes the motherboards' voltage regulators.
3DMark06 And PCMark05 Loops
In this first test we created a batch file to run the 3DMark06 with its default settings, and the system, CPU and memory tests of PCMark05. Since both terminate within minutes, we decided to loop the whole enchilada four times.
This chart shows the average power requirement while 3DMark and PCMark were looped. Clearly, the AMD solution required more energy.
We calculated the total power consumption for the duration of the 3DMark06/PCMark05 test: 339 Wh for the Athlon 64 X2 5000+ is 25% more energy than the 269 W of the Intel system. The question now is: which one took longer?
The diagram portrays the power consumption of the systems at the plug during the four repetitions of 3DMark06 (first) and PCMark05. You can observe that the spikes are repeated four times, which corresponds to the benchmark runs. You'll also notice that the Intel system (blue) took 2:15 to complete this run, while the AMD system required almost 2:20, while having an average power consumption that was ~30 W higher than that of the Intel system.