The Tech Report checks out how much power the Windows Vista Aero GUI consumes:
Much has been made of Windows Vista's new Aero interface, and for good reason. The GUI is loaded with luscious eye candy, including the liberal use of transparency, and even a few 3D effects. That eye candy doesn't come cheap, though. Aero relies on graphics hardware to accelerate the interface, and requires a DirectX 9-compatible graphics card that supports Shader Model 2.0 and has at least 128MB of memory. Those requirements are pretty steep for an operating system, but they also raise an interesting question: if Aero is accelerated with graphics hardware, will system power consumption rise as a result?