The CPU usage when running the different Flash Player options is just as would be expected. When comparing Flash Player 11 Beta 1, enabling VDPAU on the NVIDIA GeForce hardware had cut the CPU usage in half for the Intel Sandy Bridge CPU going from 17% to 8% when playing back The Dark Knight 1080p HD trailer. Even when not taking advantage of VDPAU, the Adobe Flash Player was much more efficient than Gnash. The Gnash 0.8.9 Flash Player had an average CPU usage of 29% during this time.
While using VDPAU had led to the lowest CPU usage with the Adobe Flash Player, enabling this NVIDIA video API had caused higher system power consumption. The system power consumption had gone up from 99 Watts to 120 Watts when the Video Decode and Presentation API for Unix was enabled. This change is likely attributed to the NVIDIA Linux driver pushing the GeForce GTX 460 into its maximum PowerMizer performance state when using VDPAU. Technically the GeForce GTX 460 should not need to be at full power when dealing with VDPAU video playback, but due to a driver bug or hardware design shortcoming, it is being ramped up whenever VDPAU is in use. With the NVIDIA graphics card no longer in its lower-power state, the system power consumption goes up.
In terms of the power consumption between Adobe Flash 11 Beta 1 and Gnash 0.8.9, the open-source FSF Flash Player had consumed around eight more Watts on average than the official Adobe software.