I have a strange overheating problem with the video card stated in the topic title.
I've got this problem since I bought this laptop, and installed linux (Ubuntu) on it.
I have been using linux on all my other laptops before and never ran into a problem as big as this one.
The problem is as following: When I start my computer into ubuntu, my laptop starts building up much heat.
After approximately 10 to 15 minutes my computer powers down, and needs to cool off before I can start it up again.
I've found some solutions on the internet, by forcing the power management to a low state.
Also with using proprietary drivers the problem seems to be solved.
Only i am a big fan of the open-source principle, so of course I'd like to use the open-source radeon driver.
Has anybody any idea why the open-source driver is causing overheating of the graphics card?
Also a strange thing to mention is that with the default power profile is that the graphics processor and mem. are clocked to manufacturer clock speeds.
So to my understanding my hardware should be capable of normal operation under these conditions.
Hopefully anybody can give me some clarification on this problem.

Kind regards,
Jasper