When performing intensive CUDA computations for a long time, a NVIDIA graphics device can sometimes switch to an invalid or slow state. With certain graphics cards this happens when the card runs at a high temperature for a long time. When this happens, what is needed is a way to restart the graphics device without having to restart the computer.
There does not seem to be a tool to make this happen. One way to restart the graphics device is to open the Device Manager, choose the graphics device. First Disable it, and then Enable it back. This seems to switch back the graphics device to a fresh working state.
Tried with: NVidia GeForce GTX 460 and Windows 7