Elite Bastards posted a video playback quality and performance analysis of ATI and NVIDIA based GPUs

Although playing back DVD content is easy enough with any modern CPU now, the advent of High Definition content and the rise of Blu-Ray as the winner of the next-generation optical format war have brought new and far more demanding computing requirements to the PC marketplace. While a CPU alone will struggle to handle High Definition content recorded in 1080p, modern GPUs are ideally designed and placed to take most of that workload away from the CPU, which means that the latest generations of graphics boards from both NVIDIA and AMD's ATI graphics division are capable of accelerating most if not all of a High Definition video stream.

ATI and NVIDIA - Video playback quality and performance analysis