Here is the current list of CUDA cards that are supported by CS6 - take note that this list will likely increase as nVidia's new generation of cards, Kepler, was introduced this past March.
Take note that not all cards with CUDA cores are supported by AE or PPro. FWIW, PPro CS6 supports openCL and that means some of the ATI cards. But AE CS6, as it is, only supports CUDA, or specifically, nVidia's optiX ray-tracing technology which harnesses CUDA.
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