Achaa:
Hello and welcome to the forums.
While everything you actually see on your monitor is a product of your video card augmented to some extent by your system memory, cpu as well as your hard drive (since that is where most things reside) and I think it is safe to say that Aero is not exactly a video accelerator you can also expect to see little or no negative impact on a modern well equipped machine with decent system resources. Microsoft attributes this for the most part to Aero's use of the Super Fetch feature and actually commisioned a study by an independent research company in the early days of Vista to help debunk claims by many that the Aero feature hogged to much in the way of available system resources.
Here's a link...