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I did the sudo aticonfig -f --adapter=all --initial and rebooted, I also deleted the .bin file in cgminer's directory.
CGminer gave an error about the number of devices not matching. It saw three devices, but OpenCL was only seeing one?
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opencl has nothing to do with xorg I'm afraid, but what you need before starting cgminer is:
export DISPLAY=:0
I'm not running as root. DISPLAY is already set. And I'm not using SSH, I'm on the local console.