I have got a RADEON HD 7970 sapphire on Debian Squeeze. Since I often use it with running GPU codes, sometimes the performances highly decrease as I test it with "glxgears" tool (I get only 20 FPS in fullscreen). So I would like to be able to reinitialize the GPU without reboot the system. I know the "clinfo" tool which display the features of the graphics card. Is there a tool which allows to do this reinitialization ?