NVIDIA has published on its developer zone a beta version of the NVENC SDK. NVIDIA’s latest generation of GPUs, Kepler, contains a dedicated hardware-based H.264 video encoder that does not use the 3D hardware and then uses much less power compared to the CUDA-based encoder. The NVENC SDK allows to take advantage of this H.264 hardware video encoder.
This is release 2.0 beta of NV Encode SDK. This SDK release is provided “as is” for evaluation purposes, without any guarantees of backward compatibiilty with future NVIDIA drivers. Since this is an beta release of the SDK, NVIDIA may make changes to the SDK and the API functions/structures before final release. Applications based on this SDK may need to change in that case, when final SDK is released with NVIDIA driver version 310.xx.
This NVENC SDK will work with NVIDIA display driver version 310.80 or higher.
You can download the NVENC SDK from this page.
Source: Geeks3D forum