I'm using Ubuntu 14.04 with AMD proprietary drivers. I want to replace the proprietary driver with open source because it is freezing during debugging of multi-threaded program.
I'm uninstalling the proprietary driver using
aticonfig --uninstall. Now Ubuntu switches back to open source drive but everything is slow after that.
My machine is also heating too much and it's getting thermal shutdown in a couple of minutes. I do remember installing some packages which resolved this issue but I forgot the name of the packages. I did that last year where I accidentally uninstalled a package. Live CD does not show this over heating and slowing issue.
After installing opensource drive
lsmod | grep radeon returns nothing. Which simply means that the
radeon module is not loading at startup.
$ lspci | grep VGA 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Trinity [Radeon HD 7640G] 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Thames [Radeon HD 7500M/7600M Series]