Before we bring this article to a close, we'd like to cover a few final data points. Throughout all of our benchmarking and testing, we monitored how much power our test system was consuming using a power meter and also took some notes regarding its noise output. Our goal was to give you all an idea as to how much power each configuration used and to explain how loud the configurations were under load. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the video cards alone.
In terms of peak and idle power consumption, the new Radeon HD 3650 is a clear performance-per-watt champion. Throughout our benchmarks, the Radeon HD 3650 performed about on par with, or slightly better, than the Radeon HD 2600 XT. Despite offering similar performance, however, the new card consumed 10 fewer watts while running under a full 3D workload. On top of that, the 3650 doesn't require a supplimental power connector and its PCB is significantly smaller. We can see why AMD has high hopes for this card.
As for the 3650's acoustic profile, we'd definitly consider it quiet, but not silent. The cooler's fan emits a somewhat high-pitched whine, albiet at a low volume, during normal use. We would not consider the card loud by any means, but we could see a discerning HTPC user being distracted by the cooler's report. In that case, the passive 3450 would obviously be the better choice.