NVIDIA GeForce 8600: Full H.264 Decode Acceleration

Note that the offload NVIDIA has built into the G84/G86 GPUs is hardwired for H.264 decoding only; you get none of the benefit for MPEG-2 or VC1 encoded content. Admittedly H.264 is the more strenuous of the three, but given that VC1 content is still quite prevalent among HD-DVD titles it would be nice to have. Also note that as long as your decoder supports NVIDIA's VP2/BSP, any H.264 content will be accelerated. For MPEG-2 and VC1 content, the 8600 and 8500 can only handle inverse transform, motion compensation and in-loop deblocking and the rest of the pipe is handled by the host CPU; VP1 NVIDIA hardware only handles motion compensation and in-loop deblocking. ATI's current GPUs can handle inverse transform, motion compensation and in-loop deblocking, so they should in theory have lower CPU usage than the older NVIDIA GPUs on this type of content.