Power Consumption Testing
Now we come to probably one of the most important sections of our testing and that is power consumption!
It is all good and well to have the fastest performing computing system under the sun, but one of the key factors we didn't want to forget about whilst building this AMD based HTPC was power consumption.
Using the power tester you can see in the picture above, we measured power coming from the wall - it is measuring the full system, everything inside the box. It doesn't include our LCD HDTV, speakers, amplifier and so on.
We used prime95 to fully load each CPU processor core with every tested AMD processor and a score was recorded after five minutes of loading. We recorded the highest wattage level hit and rounded up to the nearest decimal point. An idle wattage level was recorded after staying idle on the Vista desktop for five minutes and here again we also rounded up to the nearest decimal point.
Do note that AMD's Cool'n'Quiet green processor technology was enabled in the BIOS, so when active, CPU clock speed and voltages drop automatically to reduce power consumption.
As you would expect, the X4 9950 part chews up the most amount of power using up to 234-watts, while the low-end X2 4850E only uses up to 146-watts.
That will add up to a large power saving over time and is going to go a long way in deciding which processor we end up using in this system. We did want to note that the idle power consumption of the X2 4850E moved from 102-watts up to 114-watts during our testing, but stayed mostly in the 107-watt range.