My laptop has two GPUs: an integrated intel and a Radeon HD 8550M. The latter is from Radeon HD 8000 series. According to the manual of the open source Radeon driver, these series are supported by the driver. I want to use the Radeon GPU, but the integrated GPU is being used by ubuntu and the applications, and I don't know how to activate the Radeon. Thanks.
just type in console: