Physx isn't a failure but not a success either. ATI/AMD does have a working physics engine for their cards since 2006 but unlike phsyx which is free Havok FX is not and game developers do not want to foot the massive bill for that when either physx is free or regular havok is a lot cheaper. ATI cards run physics just as wel maybe better than nvidia but AMD/ATI will either have to wait for something more open or cheap to come along or develop their own. The only restriction when it comes to physx is that Nvidia won't let ati run it on their cards but allow for it to be run on the cpu instead including the consoles and even the iphone.