Nvidia’s new 340.52 drivers (that enable the new SHIELD tablet features) have a feature that disable GPU PhysX in dual-GPU systems that have one non-Nvidia card, according to Nvidia’s own release notes for the drivers in question. According to Nvidia, GPU PhysX is disabled when a non-Nvidia GPU is present because the company says a high quality experience in such a scenario can’t be guaranteed. Such a combination would preclude users from utilizing using key features such as high performance communication between CUDA and the graphics API. Unfortunately for many users Nvidia says it has not found a full-proof way to detect whether or not the non-Nvidia
